Oxazolo, thiazolo and selenazolo [4,5-c]-quinolin-4-amines and analogs thereof

ABSTRACT

Thiazolo-, oxazolo- and selenazolo[4,5-c]quinolin-4-amines and analogs thereof are described including methods of manufacture and the use of novel intermediates. The compounds are immunomodulators and induce cytokine biosynthesis, including interferon and/or tumor biosynthesis, necrosis factor, and inhibit the T-helper-type 2 immune response. The compounds are further useful in the treatment of viral and neoplastic diseases.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.09/593,434, filed Jun. 14, 2000, now pending, which is a divisional ofU.S. application Ser. No. 09/361,544, filed Jul. 27, 1999, issued asU.S. Pat. No. 6,110,929, which claims benefit of No. 60/094,346, filedJul. 28, 1998.

FIELD OF THE INVENTION

This invention relates to oxazolo, thiazolo and selenazolo[4,5-c]-quinolin-, tetrahydroquinolin-4-amines and hetero analogsthereof, and to intermediates used in their preparation. The inventionalso relates to pharmaceutical compositions containing the abovecompounds as well as the use of these compounds as immunomodulators andfor inducing cytokine biosynthesis, including interferon-α biosynthesisand/or tumor necrosis factor-α biosynthesis.

BACKGROUND OF THE INVENTION AND RELATED PRIOR ART

The first reliable report on the 1H-imidazo[4,5-c]quinoline ring system,Backman et al., J. Org. Chem. 15, 1278-1284 (1950) describes thesynthesis of1-(6-methoxy-8-quinolinyl)-2-methyl-1H-imidazo[4,5-c]quinoline forpossible use as an antimalarial agent. Subsequently, syntheses ofvarious substituted 1H-imidazo[4,5-c]quinolines have been reported. Forexample, Jain et al., J. Med. Chem. 11, pp. 87-92 (1968), hassynthesized the compound1-[2-(4-piperidyl)ethyl]-1H-imidazo[4,5-c]quinoline as a possibleanticonvulsant and cardiovascular agent. Also, Baranov et al., Chem.Abs. 85, 94362 (1976), and Berenyi et al., J. Heterocyclic Chem. 18,1537-1540 (1981), have reported certain 2-oxoimidazo[4,5-c]quinolines.

Following the above report, 1H-imidazo[4,5-c]quinolin-4-amines and 1-and 2-substituted derivatives thereof were found to be useful asantiviral agents, bronchodilators and immunomodulators. These aredescribed in U.S. Pat. Nos. 4,689,338; 4,698,348; 4,929,624; 5,037,986;5,266,675; 5,268,376; 5,346,905; 5,389,640; 5,605,899; 5,352,784;5,446,153; and 5,482,936. Shen et al., U.S. Pat. Nos. 4,038,396 and4,131,677, describe certain oxazolo- and thiazolopyridines as havingantiinflammatory, analgesic, and antipyretic properties.

SUMMARY OF THE INVENTION

The present invention provides compounds of the Formula I

wherein:

R₁ is selected from the group consisting of oxygen, sulfur and selenium;

R₂ is selected from the group consisting of

-hydrogen;

-alkyl;

-alkyl-OH;

-haloalkyl;

-alkenyl;

-alkyl-X-alkyl;

-alkyl-X-alkenyl;

-alkenyl-X-alkyl;

-alkenyl-X-alkenyl;

-alkyl-N(R₅)₂;

-alkyl-N₃;

-alkyl-O—C(O)—N(R₅)₂;

-heterocyclyl;

-alkyl-X-heterocyclyl;

-alkenyl-X-heterocyclyl;

-aryl;

-alkyl-X-aryl;

-alkenyl-X-aryl;

-heteroaryl;

-alkyl-X-heteroaryl; and

-alkenyl-X-heteroaryl;

R₃ and R₄ are each independently:

-hydrogen;

-X-alkyl;

-halo;

-haloalkyl;

—N(R₅)₂;

or when taken together, R₃ and R₄ form a fused aromatic, heteroaromatic,cycloalkyl or heterocyclic ring;

X is selected from the group consisting of —O—, —S—, —NR₅—, —C(O)—,—C(O)O—, —OC(O)—, and a bond; and

each R₅ is independently H or C₁₋₈alkyl;

with the proviso that when R₁ is sulfur, R₃ is not —NH₂; or apharmaceutically acceptable salt thereof.

As a second aspect, the present invention provides pharmaceuticalcompositions containing a therapeutically effective amount of a compoundof Formula I(a) and a pharmaceutically acceptable vehicle:

wherein:

R₁ is selected from the group consisting of oxygen, sulfur and selenium;

R₂ is selected from the group consisting of

-hydrogen;

-alkyl;

-alkyl-OH;

-haloalkyl;

-alkenyl;

-alkyl-X-alkyl;

-alkyl-X-alkenyl;

-alkenyl-X-alkyl;

-alkenyl-X-alkenyl;

-alkyl-N(R₅)₂;

-alkyl-N₃;

-alkyl-O—C(O)—N(R₅)₂;

-heterocyclyl;

-alkyl-X-heterocyclyl;

-alkenyl-X-heterocyclyl;

-aryl;

-alkyl-X-aryl;

-alkenyl-X-aryl;

-heteroaryl;

-alkyl-X-heteroaryl; and

-alkenyl-X-heteroaryl;

R₃ and R₄ are each independently:

-hydrogen;

-X-alkyl;

-halo;

-haloalkyl;

N(R₅)₂;

or when taken together, R₃ and R₄ form a fused aromatic, heteroaromatic,cycloalkyl or heterocyclic ring;

X is selected from the group consisting of —O—, —S—, —NR₅—, —C(O)—,—C(O)O—, —OC(O)—, and a bond; and

each R₅ is independently H or C₁₋₈alkyl;

or a pharmaceutically acceptable salt thereof.

The compounds of Formula I(a) are useful in inducing the biosynthesis ofcertain cytokines in animals, including humans. Cytokines that may beinduced by the compounds of the invention include but are not limitedto, interferons, particularly interferon-α, and tumor necrosis factor-α.The invention therefore also provides a method of inducing cytokinebiosynthesis in an animal by administering to the animal an effectiveamount of a composition comprising a compound of Formula I(a). Becauseof their ability to induce cytokine biosynthesis the compounds of theinvention are useful in the treatment of a variety of conditions,including viral and neoplastic diseases, and the invention furtherprovides a method of treating such conditions in a subject byadministering a therapeutically effective amount of a compositioncomprising a compound of Formula I(a) to the subject.

As yet another aspect, the present invention provides intermediatecompounds of Formula II

wherein:

R₁ is selected from the group consisting of oxygen, sulfur and selenium;

R₂ is selected from the group consisting of

-hydrogen;

-alkyl;

-alkyl-OH;

-haloalkyl;

-alkenyl;

-alkyl-X-alkyl;

-alkyl-X-alkenyl;

-alkenyl-X-alkyl;

-alkenyl-X-alkenyl;

-alkyl-N(R₅)₂;

-alkyl-N₃;

-alkyl-O—C(O)—N(R₅)₂;

-heterocyclyl;

-alkyl-X-heterocyclyl;

-alkenyl-X-heterocyclyl;

-aryl;

alkyl-X-aryl;

-alkenyl-X-aryl;

-heteroaryl;

alkyl-X-heteroaryl;

-alkenyl-X-heteroaryl;

SO₂CH₃; and

—CH₂—O—C(O)—CH₃;

R₃ and R₄ are each independently:

-hydrogen;

-X-alkyl;

-halo;

-haloalkyl;

—N(R₅)₂;

or when taken together, R₃ and R₄ form a fused aromatic, heteroaromatic,cycloalkyl or heterocyclic ring;

X is selected from the group consisting of —O—, —S—, —NR₅—, —C(O)—,—C(O)O—, and a bond; and

each R₅ is independently H or C₁₋₈alkyl.

DETAILED DESCRIPTION OF THE INVENTION

This invention includes compounds of Formula I, pharmaceuticalcompositions containing compounds of Formula I(a) and therapeuticmethods using compounds of Formula I(a) as well as intermediatecompounds of Formula II that are used to prepare the compounds ofFormulae I and I(a).

The terms “alkyl” and “alkenyl” as used herein refer to a straight orbranched hydrocarbon group, or a cyclic group (i.e., cycloalkyl andcycloalkenyl) that contains from 1 to 20, preferably 1 to 10, morepreferably 1 to 8 carbon atoms, unless otherwise specified. Typicalalkyl groups are, for example, methyl, ethyl, n-propyl, isopropyl,n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl,n-octyl, and the like. Exemplary cyclic groups include cyclopropyl,cyclopentyl, cyclohexyl, cyclohexenyl and adamantyl. The prefix “alk,”when used, e.g. for “alkoxy” and the like, also has the same meaning.

The term “aryl” refers to a carbocyclic aromatic ring or ring system.The aryl group is preferably a six-membered ring, such as phenyl, or anaromatic polycyclic ring system, such as naphthyl. The most preferredaryl group is phenyl which may be unsubstituted or substituted by one ormore substituents as defined below. Examples of other suitable arylgroups include biphenyl, fluorenyl and indenyl.

The term “heteroaryl” refers to an aromatic ring or ring system thatcontains one or more heteroatoms, in which the heteroatoms are selectedfrom nitrogen, oxygen and sulfur. Suitable heteroaryl groups includefuryl, thienyl, pyridyl, quinolinyl, tetrazolyl, imidazo, and so on. Inthe case where R₃ and R₄ are taken together and form a 5- or 6-memberedheteroaromatic ring, the heteroatom is nitrogen, oxygen or sulfur andthe ring may contain one or more of such atoms. Preferably, theheteroatom is nitrogen or sulfur. Preferred heteroaromatic rings formedby R₃ and R₄ are illustrated by the following formulae where the twolines indicate where they are fused.

The terms “heterocyclic” and “heterocyclyl” refer to non-aromatic ringsor ring systems that contain one or more ring heteroatoms (e.g., O, S,N). Exemplary heterocyclic groups include pyrrolidinyl,tetrahydrofuranyl, morpholinyl, piperidino, piperazino, thiazolidinyl,imidazolidinyl, and the like.

All of the above rings and ring systems can be unsubstituted orsubstituted by one or more substituents selected from the groupconsisting of alkyl, alkoxy, alkylthio, hydroxy, halogen, haloalkyl,polyhaloalkyl, perhaloalkyl (e.g., trifluoromethyl), trifluoroalkoxy(e.g., trifluoromethoxy), nitro, amino, alkylamino, dialkylamino,alkylcarbonyl, alkenylcarbonyl, arylcarbonyl, heteroarylcarbonyl, aryl,arylalkyl, heteroaryl, heteroarylalkyl, heterocyclyl, heterocycloalkyl,nitrile and alkoxycarbonyl. Preferred substituents are C₁₋₄ alkyl, C₁₋₄alkoxy, halo, amino, alkylamino, dialkylamino, hydroxy, C₁₋₄alkoxymethyl and trifluoromethyl.

The term “halo” refers to a halogen atom, such as, for example,fluorine, chlorine, bromine or iodine.

The invention is inclusive of the compounds described herein in any oftheir pharmaceutically acceptable forms, including isomers such asdiastereomers and enantiomers, salts, solvates, polymorphs and the like.

As noted above, the compounds of Formula I and I(a) are capable offorming “pharmaceutically acceptable salt(s).” Pharmaceuticallyacceptable acid addition salts of the compounds of Formula I and I(a)include salts derived from nontoxic inorganic acids such ashydrochloric, nitric, phosphoric, sulfuric, hydrobromic, hydriodic,hydrofluoric, phosphorous, and the like, as well as the salts derivedfrom nontoxic organic acids, such as aliphatic mono- and dicarboxylicacids, phenyl-substituted alkanoic acids, hydroxy alkanoic acids,alkanedioic acids, aromatic acids, aliphatic and aromatic sulfonicacids, etc. Such salts thus include sulfate, pyrosulfate, bisulfate,sulfite, bisulfite, nitrate, phosphate, monohydrogenphosphate,dihydrogenphosphate, metaphosphate, pyrophosphate, chloride, bromide,iodide, acetate, trifluoroacetate, propionate, caprylate, isobutyrate,oxalate, malonate, succinate, suberate, sebacate, fumarate, maleate,mandelate, benzoate, chlorobenzoate, methylbenzoate, hydroxynaphthoate,xinafoate, dinitrobenzoate, phthalate, benzenesulfonate,toluenesulfonate, phenylacetate, citrate, lactate, maleate, tartrate,methanesulfonate, and the like. Also contemplated are salts of aminoacids such as arginate and the like and gluconate, galacturonate (see,for example, Berge S M, et al., “Pharmaceutical Salts,” J. Pharm. Sci.1977;66:1).

The acid addition salts of the compounds are prepared by contacting thefree base form with a sufficient amount of the desired acid to producethe salt in the conventional manner. The free base form may beregenerated by contacting the salt form with a base and isolating thefree base in the conventional manner.

Preferred compounds of Formula I and I(a) are those wherein R₁ is oxygenor sulfur. Preferred R₂ substituents include alkyl and alkoxyalkyl, withC₁₋₄ alkyl especially preferred.

It is preferred that R₃ and R₄ be taken together to form a fused benzeneor pyridine ring that may be substituted or unsubstituted.

Most preferred compounds are those of the Formula III or IV

wherein R₂ is defined above, and R is hydrogen, alkyl, alkoxy,alkylthio, hydroxy, halogen, haloalkyl, polyhaloalkyl, perhaloalkyl(e.g., trifluoromethyl), trifluoroalkoxy (e.g., trifluoromethoxy),nitro, amino, alkylamino, dialkylamino, alkylcarbonyl, alkenylcarbonyl,arylcarbonyl, heteroarylcarbonyl, aryl, arylalkyl, heteroaryl,heteroarylalkyl, heterocyclyl, heterocycloalkyl, nitrile andalkoxycarbonyl.

Exemplary compounds of the invention include:

2-methylthiazolo[4,5-c]quinolin-4-amine;

thiazolo[4,5-c]quinolin-4-amine;

2-ethylthiazolo[4,5-c]quinolin-4-amine;

2-propylthiazolo[4,5-c]quinolin-4-amine;

2-pentylthiazolo[4,5-c]quinolin-4-amine;

2-butylthiazolo[4,5-c]quinolin-4-amine;

2-(1-methylethyl)thiazolo[4,5-c]quinolin-4-amine;

2-(2-phenyl-1-ethenyl)thiazolo[4,5-c]quinolin-4-amine;

2-(2-phenyl-1-ethyl)thiazolo[4,5-c]quinolin-4-amine;

2-(4-aminothiazolo[4,5-c]quinolin-2-yl)-1,1-dimethylethyl carbamate;

2-(ethoxymethyl)thiazolo[4,5-c]quinolin-4-amine;

2-(methoxymethyl)thiazolo[4,5-c]quinolin-4-amine;

2-(2-methylpropyl)thiazolo[4,5-c]quinolin-4-amine;

2-benzylthiazolo[4,5-c]quinolin-4-amine;

8-methyl-2-propylthiazolo[4,5-c]quinolin-4-amine;

(4-aminothiazolo[4,5-c]quinolin-2-yl)methanol;

2-methyloxazolo[4,5-c]quinolin-4-amine;

2-ethyloxazolo[4,5-c]quinolin-4-amine;

2-butyloxazolo[4,5-c]quinolin-4-amine;

2-propylthiazolo[4,5-c]quinolin-4,8-diamine;

2-propyloxazolo[4,5-c]quinolin-4-amine;

8-bromo-2-propylthiazolo[4,5-c]quinolin-4-amine;

7-methyl-2-propylthiazolo[4,5-c]quinolin-4-amine;

2-butyl-7-methyloxazolo[4,5-c]quinolin-4-amine;

7-methyl-2-propyloxazolo[4,5-c]quinolin-4-amine;

7-fluoro-2-propyloxazolo[4,5-c]quinolin-4-amine;

7-fluoro-2-propylthiazolo[4,5-c]quinolin-4-amine;

2-propyl-7-(trifluoromethyl)thiazolo[4,5-c]quinolin-4-amine;

2-(4-morpholino)thiazolo[4,5-c]quinolin-4-amine;

2-( 1-pyrrolidino)thiazolo[4,5-c]quinolin-4-amine;

2-butylthiazolo[4,5-c][1,5]naphthyridin-4-amine;

2-propylthiazolo[4,5-c][1,5]naphthyridin-4-amine;

7-chloro-2-propylthiazolo[4,5-c]quinolin-4-amine;

7-methoxy-2-propylthiazolo[4,5-c]quinolin-4-amine;

and pharmaceutically acceptable salts thereof, particularly thehydrochloride salts thereof.

Preparation of the Compounds

Compounds of the invention can be prepared according to Reaction SchemeI wherein R₁, R₂, R₃ and R₄ are as defined above.

In step (1) of Reaction Scheme I a compound of Formula V is reacted witha carboxylic acid or an equivalent thereof to provide a compound ofFormula VI. Suitable equivalents to carboxylic acid include acidanhydrides, acid chlorides, orthoesters and 1,1-dialkoxyalkanoates. Thecarboxylic acid or equivalent is selected such that it will provide thedesired R₂ substituent in a compound of Formula VI. For example,triethyl orthoformate will provide a compound of Formula VI where R₂ ishydrogen and acetic anhydride will provide a compound of Formula VIwhere R₂ is methyl. The reaction can be run in the absence of solvent,in the presence of an acid such as polyphosphoric acid, or preferably inthe presence of a carboxylic acid of the formula R₂C(O)OH. The reactionis run with sufficient heating to drive off any alcohol or water formedas a byproduct of the reaction. The compounds of Formula V are known ormay be prepared using conventional methods (see for example, Bachman et.al., Journal of the American Chemical Society, 69, pp 365-371 (1947);Ambrogi et. al., Synthesis, pp. 656-658 (1992); Adler et. al., Journalof the Chemical Society, pp.1794-1797 (1960); Süs et. al., JustusLiebigs Annalen der Chemie, 583, pp. 150-160 (1953); and Süs et. al.,Justus Liebigs Annalen der Chemie, 593, pp. 91-126 (1955).

In step (2) of Reaction Scheme I a compound of Formula VI is oxidized toprovide an N-oxide of Formula II. The oxidation is carried out using aconventional oxidizing agent that is capable of forming N-oxides.Preferred reaction conditions involve reacting a solution of a compoundof Formula VI in chloroform with 3-chloroperoxybenzoic acid at ambientconditions. Alternatively the oxidation may be carried out usingperacetic acid in a suitable solvent such as ethyl or methyl acetate.

In step (3) of Reaction Scheme I an N-oxide of Formula II is aminated toprovide a compound of Formula I. Step (3) involves (i) reacting acompound of Formula II with an acylating agent and then (ii) reactingthe product with an aminating agent. Part (i) of step (3) involvesreacting an N-oxide of Formula II with an acylating agent. Suitableacylating agents include alkyl- or arylsulfonyl chlorides (e.g.,benezenesulfonyl chloride, methanesulfonyl chloride, p-toluenesulfonylchloride). Arylsulfonyl chlorides are preferred. Para-toluenesulfonylchloride is most preferred. Part (ii) of step (3) involves reacting theproduct of part (i) with an excess of an aminating agent. Suitableaminating agents include ammonia (e.g., in the form of ammoniumhydroxide) and ammonium salts (e.g., ammonium carbonate, ammoniumbicarbonate, ammonium phosphate). Ammonium hydroxide is preferred. Thereaction is preferably carried out by dissolving or suspending theN-oxide of Formula II in an inert solvent such as dichloromethane orchloroform, adding the aminating agent to the solution or suspension,and then slowly adding the acylating agent. The product or apharmaceutically acceptable salt thereof can be isolated usingconventional methods.

Alternatively, step (3) can be carried out by (i) reacting an N-oxide ofFormula II with an isocyanate and then (ii) hydrolyzing the resultingproduct. Part (i) involves reacting the N-oxide with an isocyanatewherein the isocyanato group is bonded to a carbonyl group. Preferredisocyanates include trichloroacetyl isocyanante and aroyl isocyanatessuch as benzoyl isocyanate. The reaction of the isocyanate with theN-oxide is carried out under substantially anhydrous conditions byadding the isocyanate to a solution of the N-oxide in an inert solventsuch as dichloromethane. Part (ii) involves hydrolysis of the productfrom part (i). The hydrolysis can be carried out by conventional methodssuch as heating in the presence of water or a lower alkanol optionallyin the presence of a catalyst such as an alkali metal lower alkoxide orammonia.

Compounds of the invention wherein R₁ is oxygen or sulfur and R₃and R₄together form an optionally substituted aromatic ring can be preparedaccording to Reaction Scheme II wherein R and R₂ are as defined above.

In step (1) of Reaction Scheme II a 3-aminoquinolin-4-ol or3-aminoquinolin-4-thiol of Formula VII is reacted with a carboxylic acidor an equivalent thereof to provide an oxazolo- orthiazolo[4,5-c]quinoline of Formula VIII. Suitable equivalents tocarboxylic acid include acid anhydrides, acid chlorides, orthoesters and1,1-dialkoxyalkanoates. The carboxylic acid or equivalent is selectedsuch that it will provide the desired R₂ substituent in a compound ofFormula VIII. For example, tri ethyl orthoformate will provide acompound of Formula VIII where R₂ is hydrogen and acetic anhydride willprovide a compound of Formula VIII where R₂ is methyl. The reaction canbe run in the absence of solvent, in the presence of an acid such aspolyphosphoric acid, or preferably in the presence of a carboxylic acidof the formula R₂C(O)OH. The reaction is run with sufficient heating todrive off any alcohol or water formed as a byproduct of the reaction.The 3-aminoquinolin-4-ols and 3-aminoquinolin-4-thiols of Formula VIIare known or may be prepared using known methods.

In step (2) of Reaction Scheme II an oxazolo- orthiazolo[4,5-c]quinoline of Formula VIII is oxidized to provide anoxazolo- or thiazolo[4,5-c]quinolin-5N-oxide of Formula IX which is asubgenus of Formula II. The oxidation is carried out using aconventional oxidizing agent that is capable of forming N-oxides.Preferred reaction conditions involve reacting a solution of a compoundof Formula VIII in chloroform with 3-chloroperoxybenzoic acid at ambientconditions. Alternatively the oxidation may be carried out usingperacetic acid in a suitable solvent such as ethyl or methyl acetate.

In step (3) of Reaction Scheme II an N-oxide of Formula IX is aminatedto provide an oxazolo[4,5-c]quinolin-4-amine of Formula III or athiazolo[4,5-c]quinolin-4-amine of Formula IV both of which aresubgenera of Formula I. Step (3) involves (i) reacting a compound ofFormula IX with an acylating agent and then (ii) reacting the productwith an aminating agent. Part (i) of step (3) involves reacting anN-oxide of Formula IX with an acylating agent. Suitable acylating agentsinclude alkyl- or arylsulfonyl chlorides (e.g., benezenesulfonylchloride, methanesulfonyl chloride, p-toluenesulfonyl chloride).Arylsulfonyl chlorides are preferred. Para-toluenesulfonyl chloride ismost preferred. Part (ii) of step (3) involves reacting the product ofpart (i) with an excess of an aminating agent. Suitable aminating agentsinclude ammonia (e.g., in the form of ammonium hydroxide) and ammoniumsalts (e.g., ammonium carbonate, ammonium bicarbonate, ammoniumphosphate). Ammonium hydroxide is preferred. The reaction is preferablycarried out by dissolving or suspending the N-oxide of Formula IX in aninert solvent such as dichloromethane or chloroform, adding theaminating agent to the solution or suspension, and then slowly addingthe acylating agent. The product or a pharmaceutically acceptable saltthereof can be isolated using conventional methods.

Alternatively, step (3) can be carried out by (i) reacting an N-oxide ofFormula IX with an isocyanate and then (ii) hydrolyzing the resultingproduct. Part (i) involves reacting the N-oxide with an isocyanatewherein the isocyanato group is bonded to a carbonyl group. Preferredisocyanates include trichloroacetyl isocyanante and aroyl isocyanatessuch as benzoyl isocyanate. The reaction of the isocyanate with theN-oxide is carried out under substantially anhydrous conditions byadding the isocyanate to a solution of the N-oxide in an inert solventsuch as dichloromethane. Part (ii) involves hydrolysis of the productfrom part (i). The hydrolysis can be carried out by conventional methodssuch as heating in the presence of water or a lower alkanol optionallyin the presence of a catalyst such as an alkali metal lower alkoxide orammonia.

Compounds of the invention wherein R₁ is sulfur can also be preparedaccording to Reaction Scheme III wherein R₂, R₃ and R₄ are as definedabove.

In step (1) of Reaction Scheme III a compound of Formula X is reactedwith an acyl halide of formula R₂C(O)Z wherein R₂ is as defined aboveand Z is chloro or bromo to provide an amide of Formula XI. The reactioncan be carried out by adding the acyl halide in a controlled fashion(e.g., dropwise) to a solution or suspension of a compound of Formula Xin a suitable solvent such as pyridine or dichloromethane in thepresence of a tertiary amine.

In step (2) of Reaction Scheme III an amide of Formula XI is reactedwith phosphorous pentasulfide to provide a compound of Formula XII. Thereaction can be carried out by adding phosphorous pentasulfide to asolution or suspension of a compound of Formula XI in a suitable solventsuch as pyridine and heating the resulting mixture.

Steps (3) and (4) of Reaction Scheme III can be carried out in the samemanner as steps (2) and (3) of Reaction Scheme I respectively to providean N-oxide of Formula XIII which is a subgenus of Formula II and acompound of Formula XIV which is a subgenus of Formula I respectively.

Compounds of the invention wherein R₁ is sulfur and R₃ and R₄ togetherform an optionally substituted aromatic ring can also be preparedaccording to Reaction Scheme IV wherein R and R₂ are as defined above.

In step (1) of Reaction Scheme IV a 3-aminoquinolin-4-ol of Formula XVis reacted with an acyl halide of formula R₂C(O)Z wherein R₂ is asdefined above and Z is chloro or bromo to provide anN-(4-hydroxyquinolin-3-yl)amide of Formula XVI. The reaction can becarried out by adding the acyl halide in a controlled fashion (e.g.,dropwise) to a solution or suspension of a compound of Formula XV in asuitable solvent such as dichloromethane in the presence of a tertiaryamine.

In step (2) of Reaction Scheme IV an N-(4-hydroxyquinolin-3-yl)amide ofFormula XVI is reacted with phosphorous pentasulfide to provide athiazolo[4,5-c]quinoline of Formula XVII. The reaction can be carriedout by adding phosphorous pentasulfide to a solution or suspension of acompound of Formula XVI in a suitable solvent such as pyridine andheating the resulting mixture.

Steps (3) and (4) of Reaction Scheme IV can be carried out in the samemanner as steps (2) and (3) of Reaction Scheme II respectively toprovide a thiazolo[4,5-c]quinolin-5N-oxide of Formula XVIII which is asubgenus of Formula II and a thiazolo[4,5-c]quinolin-4-amine of FormulaIV which is a subgenus of Formula I respectively.

Substituents at the 2-position can be introduced by reacting a compoundof Formula XIX

wherein R₁ is oxygen or sulfur and R is as defined above, with alithiating agent such as lithium diisopropylamide or n-butyllithium in apolar aprotic solvent to provide a compound lithiated on the 2-methylgroup. The lithiated compound can then be reacted with an appropriatereagent containing a leaving group capable of being displaced by thelithiated 2-methyl group. Examples of suitable reagents include halidessuch as methyl iodide or chloromethylmethylether, aldehydes such asbenzaldehyde, and ketones such as acetone. The compounds can then beoxidized and aminated using the methods described above to providecompounds of Formulas m or IV.

Some compounds of Formula I may be prepared directly from othercompounds of Formula I. For example, nitration of2-propylthiazolo[4,5-c]quinolin-4-amine provides8-nitro-2-propylthiazolo[4,5-c]quinolin-4-amine and the reduction of thenitro compound provides 2-propylthiazolo[4,5-c]quinoline-4,8-diamine.

Pharmaceutical Compositions and Biological Activity

Pharmaceutical compositions of the invention contain a therapeuticallyeffective amount of a compound of Formula I(a) together with apharmaceutically acceptable carrier.

As used herein, the term “a therapeutically effective amount” means anamount of the compound sufficient to induce a desired therapeuticeffect, such as cytokine biosynthesis, antitumor activity and/orantiviral activity. Although the exact amount of active compound used ina pharmaceutical composition of the invention will vary according tofactors known to those of skill in the art, such as the physical andchemical nature of the compound as well as the nature of the carrier,the intended dosing regimen and the condition to be treated, it isanticipated that the compositions of the invention will containsufficient active ingredient to provide a dose of about 100 ng/kg toabout 50 mg/kg, preferably about 10 μg/kg to about 5 mg/kg of thecompound to the subject. Any of the conventional dosage forms may beused, such as tablets, lozenges, parenteral formulations, syrups,creams, ointments, aerosol formulations, transdermal patches,transmucosal patches and so on. The dosage form used will also depend onthe characteristics of the compound to be administered. For example,certain compounds of Formula I(a), especially those wherein R₁ issulfur, tend to have relatively low oral bioavailability and are rapidlymetabolized when they enter the bloodstream. These properties make suchcompounds particularly well suited for treatment of conditions wheretopical administration of an immune response modifying compound isdesirable, such as asthma, basal cell carcinoma, cervicalintraepithelial neoplasia and so on.

The compounds of the invention have been shown to induce the productionof certain cytokines in experiments performed according to the TestMethod set forth below. These results indicate that the compounds areuseful as immune response modifiers that can modulate the immuneresponse in a number of different ways, rendering them useful in thetreatment of a variety of disorders.

Cytokines that are induced by the administration of compounds accordingto the invention generally include interferon-α (IFN-α) and/or tumornecrosis factor-α (TNF-α) as well as certain interleukins (IL).Cytokines whose biosynthesis may be induced by compounds of theinvention include IFN-α, TNF-α, IL-1, 6, 10 and 12, and a variety ofother cytokines. Among other effects, cytokines inhibit virus productionand tumor cell growth, making the compounds useful in the treatment oftumors and viral diseases.

In addition to the ability to induce the production of cytokines, thecompounds of the invention affect other aspects of the innate immuneresponse. For example, natural killer cell activity may be stimulated,which effect may be due to cytokine induction. The compounds may alsoactivate macrophages, which in turn stimulates secretion of nitric oxideand the production of additional cytokines. Further, the compounds maycause proliferation and differentiation of B-lymphocytes and may beuseful in the in vitro maturation of dendritic cells.

Compounds of the invention also have an effect on the acquired immuneresponse. For example, although there is not believed to be any directeffect on T cells or direct induction of T cell cytokines, theproduction of the T helper type 1 (Th1) cytokine IFN-γ is inducedindirectly and the production of the T helper type 2 (Th2) cytokinesIL-4, IL-5 and IL-13 are inhibited upon administration of the compounds.This activity means that the compounds are useful in the treatment ofdiseases where upregulation of the Th1 response and/or down regulationof the Th2 response is desired. In view of the ability of compounds ofFormula Ia to inhibit the Th2 immune response, the compounds areexpected to be useful in the treatment of atopy, e.g., atopicdermatitis, asthma, allergy, allergic rhinits, and systemic lupuserythematosis; as a vaccine adjuvant for the enhancement of cellmediated immunity; and possibly as a treatment for recurrent fungaldiseases and chlamydia.

The immune response modifying effects of the compounds make them usefulin the treatment of a wide variety of conditions. Because of theirability to induce cytokines such as IFN-α and/or TNF-α, the compoundsare particularly useful in the treatment of viral diseases and tumors.This immunomodulating activity suggests that compounds of the inventionare useful in treating diseases such as, but not limited to, viraldiseases e.g., genital warts, common warts, plantar warts, Hepatitis B,Hepatits C, Herpes Simplex Type I and Type II, molluscum contagiosm,HIV, CMV, VZV, cervical intraepithelial neoplasia, human papillomavirusand associated neoplasias; fungal diseases, e.g., candida, aspergillus,cryptococcal meningitis; neoplastic diseases, e.g., basal cellcarcinoma, hairy cell leukemia, Kaposi's sarcoma, renal cell carcinoma,squamous cell carcinoma, myelogenous leukemia, multiple myeloma,melanoma, non-Hodgkin's lymphoma, cutaneous T-cell lymphoma, and othercancers; parasitic diseases, e.g., pneumocystis carnii,cryptospordiosis, histoplasmosis, toxoplasmosis, trypanosome infection,leishmaniasis; and bacterial infections, e.g., tuberculosis,mycobacterium avium. Additional diseases or conditions that can betreated using the compounds of the invention include eczema,eosinophilia, essential thrombocythaemia, leprosy, multiple sclerosis,Ommen's syndrome, rheumatoid arthritis, systemic lupus erythematosis,discoid lupus, Bowen's disease, Bowenoid papulosis, and to enhance orstimulate the healing of wounds, including chronic wounds.

Accordingly, the invention provides a method of inducing cytokinebiosynthesis in an animal comprising administering an effective amountof a compound of Formula Ia to the animal. An amount of a compoundeffective to induce cytokine biosynthesis is an amount sufficient tocause one or more cell types, such as monocytes, macrophages, dendriticcells and B-cells to produce an amount of one or more cytokines such as,for example, IFN-60 , TNF-α, IL-1,6,10 and 12 that is increased over thebackground level of such cytokines. The precise amount will varyaccording to factors known in the art but is expected to be a dose ofabout 100 ng/kg to about 50 mg/kg, preferably about 10 μg/kg to about 5mg/kg. The invention also provides a method of treating a viralinfection in an animal comprising administering an effective amount of acompound of Formula Ia to the animal. An amount effective to treat orinhibit a viral infection is an amount that will cause a reduction inone or more of the manifestations of viral infection, such as virallesions, viral load, rate of virus production, and mortality as comparedto untreated control animals. The precise amount will vary according tofactors known in the art but is expected to be a dose of 100 ng/kg toabout 50 mg/kg, preferably about 10 μg/kg to about 5 mg/kg.

Compounds of the invention may be administered to the subject as thesole therapeutic agent, or may form part of a therapeutic regimen incombination with one or more other agents. Examples of suitable agentsthat may be used in combination with the immune response modifyingcompounds of the invention include, but are not limited to, analgesics,antibacterials, antifungals, antiinflammatory agents, antitumor agents,antivirals, bronchodilators, narcotics, and steroids.

The following examples are provided to illustrate the invention, butshould not be considered to be limiting in any way.

EXAMPLES Example 1

Part A

A suspension of 3-aminoquinoline-4-thiol (about 12 g) in a mixture ofacetic anhydride (150 mL) and acetic acid (300 mL) was heated at refluxovernight. The reaction mixture was filtered to remove a fine solid. Thefiltrate was evaporated under vacuum. The residue was diluted withethanol then refluxed for 30 minutes. The solution was concentratedunder vacuum and the residue diluted with water. The aqueous residue wasmade basic with sodium hydroxide and then extracted with diethyl ether.The ether extracts were combined, dried over magnesium sulfate andfiltered. The filtrate was evaporated to provide 12.8 g of crudeproduct. A sample (800 mg) was recrystallized from hexane to provide2-methylthiazolo[4,5-c]quinoline as yellow needles, m.p. 95.5-97.5° C.Analysis: Calculated for C₁₁H₈N₂S: %C, 65.97; %H, 4.03; %N, 13.99;Found: %C, 65.96; %H, 4.16; %N 14.08.

Part B

2-Methylthiazolo[4,5-c]quinoline (5.0 g, 25 mmol), 3-chloroperoxybenzoicacid (9.5 g of 50-60%), and dichloromethane (150 mL) were combined andstirred at ambient temperature for 3 hours. The reaction solution wasdiluted with dichloromethane (300 mL) and then extracted with aqueoussodium carbonate to remove the acids. The organic layer was washed withwater, diluted with ethyl acetate to remove cloudiness, dried overmagnesium sulfate, and then concentrated under vacuum to provide 4.5 gof crude product. A small portion was recrystallized from methanol toprovide yellow needles of 2-methylthiazolo[4,5-c]quinoline-5N-oxidehydrate, m.p. 150-160° C. Analysis: Calculated for C₁₁H₁₈N₂OS+0.75 H₂O:%C, 57.50; %H, 4.17; %N, 12.19; Found: %C, 57.58; %H, 4.10; %N, 11.93.

Example 2

2-Methylthiazolo[4,5-c]quinoline-5N-oxide (1.5 g, 6.9 mmol) was added toa mixture of dichloromethane (10 mL) and ammonium hydroxide (25 mL). Asolution of tosyl chloride (2.0 g, 10.4 mmol) in dichloromethane (10 mL)was added with vigorous stirring to the reaction mixture. The reactionwas refluxed with additional dichloromethane and ammonium hydroxidebeing added until thin layer chromatography indicated that the reactionwas complete. The dichloromethane was distilled from the mixture andyellow product was filtered from the aqueous residue. The solid waswashed with water and then dried to provide 1.2 g of crude product. Thesolid was dissolved in dilute hydrochloric acid. The solution wastreated with charcoal and then filtered. The filtrate was made basicwith dilute sodium hydroxide. The resulting precipitate was isolated byfiltration, washed with water, dried and then recrystallized frommethanol/dichloromethane to provide 0.46 g of2-methylthiazolo[4,5-c]quinolin-4-amine as a white powder, m.p. 184-187°C. Analysis: Calculated for C₁₁H₉N₃S: %C, 61.37; %H, 4.21; %N, 19.52;Found: %C, 61.32; %H, 4.52; %N, 19.68.

Example 3 2-Methylthiazolo[4,5-c]quinolin-4-amine Alternative Synthesis

Trichloroacetyl isocyanate (2.0 mL, 16.8 mmol) was added to a suspensionof 2-methylthiazolo[4,5-c]quinoline-5N-oxide (3.03 g, 14.0 mmol) indichloromethane (150 mL). The reaction mixture was stirred at ambienttemperature for about 50 minutes. The dichloromethane was concentratedunder vacuum to provide crudeN-(2-methylthiazolo[4,5-c]quinolin-4-yl)trichloroacetamide. The amidewas dissolved in methanol and then sodium methoxide (1 mL of 25% sodiummethoxide in methanol) was added. The reaction was heated at reflux for40 minutes then the methanol was evaporated under vacuum. The resultingbrown solid was washed with water and dried to provide 2.85 g of crudeproduct. This material was treated with charcoal and then recrystallizedfrom ethyl acetate to provide 2-methylthiazolo[4,5-c]quinolin-4-amine asa solid, m.p. 184-186° C. Analysis: Calculated for C₁₁H₉N₃S: %C, 61.37;%H, 4.21; %N, 19.52; Found: %C, 61.48; %H, 4.17; %N, 19.60.

Example 4 2-Methylthiazolo[4,5-c]quinolin-4-amine Hydrochloride

Concentrated hydrochloric acid (0.2 mL of 12.1M) was added to a solutionof 2-methylthiazolo[4,5-c]quinolin-4-amine (0.5 g) in methanol (15 mL).Isopropanol (15 mL) was added and then the reaction mixture was heatedat reflux to remove the majority of the methanol. The resultingprecipitate was isolated by filtration, washed with isopropanol anddried to provide 2-methylthiazolo[4,5-c]quinolin-4-amine hydrochlorideas a solid, m.p. 323-325° C. Analysis: Calculated for C₁₁H₉N₃S.HCl: %C,52.48; %H, 4.00; %N, 16.69; Found: %C, 52.46; %H, 4.08; %N, 16.52.

Example 5 Thiazolo[4,5-c]quinolin-4-amine Hydrochloride Hydrate

Part A

3-Aminoquinoline-2-thiol (about 18.5 g) was added to triethylorthoformate (26.0 mL). The reaction mixture was heated on a steam bathfor 20 minutes. Formic acid (400 mL) was added and the reaction mixturewas heated at reflux overnight. The bulk of the formic acid wasevaporated under vacuum. The residue was combined with ethanol andheated at reflux for 30 minutes. The ethanol was evaporated undervacuum. The residue was suspended in water and then made basic by addingsodium hydroxide. A precipitate formed. The solid was extracted withseveral portions of dichloromethane. The extracts were combined, driedover magnesium sulfate and then concentrated to provide a yellow solidwhich was recrystallized from hexanes to provide 13.1 g ofthiazolo[4,5-c]quinoline as a yellow crystalline solid, m.p. 104-106° C.

Part B

Peracetic acid (21 mL of 32% in acetic acid, 100 mmol) was added to asuspension of thiazolo[4,5-c]quinoline (12.5 g, 67 mmol) in methylacetate (300 mL). The reaction mixture was heated at reflux overnightand then cooled to ambient temperature. A precipitate was isolated byfiltration and then suspended in water (100 mL). Aqueous sodiumbicarbonate (100 mL) was added to the suspension and the mixture wasstirred for one hour. The solid thiazolo[4,5-c]quinoline-5N-oxide wasisolated by filtration, washed with water and dried.

Part C

Trichloroacetyl isocyanate (0.72 mL, 6.0 mmol) was added to a suspensionof thiazolo[4,5-c]quinoline-5N-oxide (1.10 g, 5.4 mmol) indichloromethane (100 mL). The reaction mixture was stirred at ambienttemperature for 45 minutes and then the dichloromethane was evaporatedunder vacuum to provide crude N-(thiazolo[4,5-c]quinolin-4-yl)trichloroacetamide. The amide was combinedwith 2M ammonia in methanol and stirred at ambient temperature for 2hours. The methanol was evaporated under vacuum. The residue wassuspended in water, combined with sodium carbonate and then stirred for10 minutes. A brown solid was collected, washed with water and dried.The solid was suspended in water, hydrochloric acid (100 mL of 6N) wasadded and the mixture was heated on a steam bath. The mixture wasfiltered; then the filtrate was allowed to slowly cool to ambienttemperature. The resulting precipitate was isolated by filtration andthen dried to provide 0.75 g of brown needles. This material wasdissolved in water (100 mL) with heating. Charcoal was added and themixture was heated with stirring for 5 minutes. The mixture was filteredthrough a layer of Celite® filter agent. The filtrate was heated on asteam bath to remove most of the water and then allowed to cool toambient temperature. The precipitate was isolated by filtration anddried to provide 0.30 g of thiazolo[4,5-c]quinolin-4-amine hydrochloridehydrate as a white crystalline solid, m.p. 284-285° C. Analysis:Calculated for C₁₀H₇N₃S.HCl.H₂O: %C, 46.97; %H, 3.94; %N, 16.43; Found:%C, 46.96; %H, 3.99; %N, 16.34.

Example 6

Part A

Thiazolo[4,5-c]quinoline-2-thiol (8.7 g, 0.04 mole) was suspended in asolution of sodium hydroxide (1.4 g, 0.04 mole) in water. A few drops of50% sodium hydroxide were added to the suspension until most of thesolid dissolved. Hydrogen peroxide (13.5 mL of 30%, 0.08 mole) was addeddropwise over a period of 30 minutes while maintaining the temperatureof the reaction mixture at 25-35° C. with a cold water bath. The bathwas removed and the reaction mixture was stirred for 15 minutes.Sulfuric acid (2.5 g of 95.98%) was added dropwise to the reactionmixture. After 30 minutes the reaction was made basic (pH 9-9.5) with50% sodium hydroxide. The reaction mixture was acidified (pH 2.5) withhydrochloric acid, a tan solid precipitated. The mixture was then heatedon a steam bath for 15 minutes and the precipitate dissolved. Thesolution was allowed to cool to ambient temperature and a precipitateformed. The mixture was made basic (pH 9) with 50% sodium hydroxide. Theresulting oily product was extracted with ethyl acetate. The extractswere combined, washed with water, dried over magnesium sulfate and thenconcentrated under vacuum to provide 3.3 g of thiazolo[4,5-c]quinolineas a tan solid, m.p. 104.4-105° C. Analysis: Calculated for C₁₀H₆N₂S:%C, 64.19; %H, 3.25; %N, 15.04; Found: %C, 64.15; %H, 3.26; %N, 14.9.

Part B

Peracetic acid (4.7 mL of 32%) was added to a solution ofthiazolo[4,5-c]quinoline (2.8 g) in methyl acetate. A precipitate formedafter several minutes. The reaction mixture was heated to reflux andthen diluted with an additional 10 mL of methyl acetate. Most of theprecipitate dissolved. After 1 hour an additional 3.1 mL of peraceticacid was added. The reaction mixture was heated overnight and thenallowed to cool to ambient temperature. The methyl acetate and aceticacid were azeotroped off with heptane. The resulting oily product wassuspended in water. The mixture was made basic with saturated sodiumbicarbonate and then extracted with ethyl acetate. The ethyl acetateextracts were combined, washed with water, dried over magnesium sulfateand then concentrated under vacuum to provide 0.6 g ofthiazolo[4,5-c]quinoline-5N-oxide as an orange solid, m.p. 178.4° C.(dec).

Part C

A solution of tosyl chloride (0.3 g) in water was added dropwise to acooled (5° C.) suspension of thiazolo[4,5-c]quinoline-5N-oxide (0.3 g)in a mixture of ammonium hydroxide (5 mL) and dichloromethane (50 mL).The temperature was maintained at 4-6° C. throughout the addition. Afterthe addition was complete the reaction mixture was stirred at ambienttemperature for 4 hours. Analysis by thin layer chromatography showedthe presence of starting material. The reaction mixture was cooled and 1equivalent of tosyl chloride was added. The reaction mixture was stirredat ambient temperature for 20 hours. The dichloromethane was evaporatedunder vacuum. The residue was slurried in a small amount of water. Themixture was filtered. The isolated solid was washed with water, driedand then recrystallized from isopropanol to provide 0.2 g ofthiazolo[4,5-c]quinolin-4-amine as an orange powder, m.p. 172.4° C.(dec). Analysis: Calculated for C₁₀H₇N₃S: %C, 59.68; %H, 3.50; %N,20.88; Found: %C, 59.82; %H, 3.20; %N, 19.50.

Example 7

Part A

Under a nitrogen atmosphere, 2-methylthiazolo[4,5-c]quinoline (1.0 g,10.0 mmol, Example 2 or 3) was placed in a dried flask. Anhydroustetrahydrofuran (50 mL) was added and the reaction mixture was cooled to−78° C. with a dry ice bath. Lithium diisopropylamide (6.7 mL of 1.5 Min hexane, 10.0 mmol) was added dropwise. 30 minutes later methyl iodide(0.95 mL, 15.0 mmol) was added. After 40 minutes the reaction wasallowed to warm to ambient temperature. The reaction mixture wasquenched with water and then extracted with diethyl ether (250 mL). Theextract was washed with water (3×100 mL), dried over magnesium sulfateand then concentrated under vacuum to provide 2.8 g of a brown oil. Thismaterial was purified using high performance liquid chromatographyeluting with 3:1 hexane:ethyl acetate to provide 1.47 g of2-ethylthiazolo[4,5-c]quinoline as a yellow oil.

Part B

3-Chloroperoxybenzoic acid (0.44 g) was added to a solution of2-ethylthiazolo[4,5-c]quinoline (0.53 g) in chloroform (20 mL). Thereaction mixture was stirred at ambient temperature for 2 hours and thendiluted with dichloromethane (20 mL), washed with sodium bicarbonate,washed with water (3×100 mL), dried over magnesium sulfate and thenconcentrated under vacuum. The resulting yellow solid was recrystallizedfrom ethyl acetate to provide 0.32 g of2-ethylthiazolo[4,5-c]quinoline-5N-oxide as a solid, m.p. 128° C.Analysis: Calculated for C₁₂H₁₀N₂OS: %C, 62.59 %H, 4.38; %N, 12.16;Found: %C, 62.59; %H, 4.27; %N, 12.12.

Example 8

Part A

Trichloroacetyl isocyanate (0.51 mL, 4.3 mmol) was added to a suspensionof 2-ethylthiazolo[4,5-c]quinoline-5N-oxide (0.90 g, 3.9 mmol) indichloromethane (60 mL). The reaction mixture was stirred at ambienttemperature for 30 minutes and then concentrated under vacuum to provide1.80 g of N-(2-ethylthiazolo[4,5-c]quinolin-4-yl)trichloroacetamide as ayellow solid.

Part B

N-(2-ethylthiazolo[4,5-c]quinolin-4-yl)trichloroacetamide (0.40 g) wassuspended in a solution of ammonia in methanol (20 mL of 2M) and thenstirred at ambient temperature for 30 minutes. The reaction mixture wasconcentrated under vacuum. The residue was washed with water and thendried to provide 0.19 g of crude product which was recrystallized fromethyl acetate/hexane to provide 2-ethylthiazolo[4,5-c]quinolin-4-amineas tan needles, m.p. 170-172° C. Analysis: Calculated for C₁₂H₁₁N₃S: %C,62.85; %H, 4.83; %N, 18.32; Found: %C, 62.58; %H, 4.78; %N, 18.08.

Example 9 2-Ethylthiazolo[4,5-c]quinolin-4-amine Alternative Synthesis

Part A

Propionyl anhydride (20 mL) was added to a suspension of3-amino-quinoline-4-thiol (15 g) in propionic acid (100 mL). Thereaction mixture was heated at reflux overnight and then filtered toremove a precipitate. The filtrate was concentrated under vacuum. Theresidue was taken up in dichloromethane (200 mL), washed with sodiumbicarbonate then with water, and then dried over magnesium sulfate. Thesolution was filtered through a layer of silica gel eluting first with1:1 ethyl acetate:hexane and then with ethyl acetate. The filtrate wasevaporated to provide 2.6 g of 2-ethylthiazolo[4,5-c]quinoline as ayellow oil.

Part B

Peracetic acid (7.4 mL of 32%) was added to a solution of2-ethylthiazolo[4,5-c]quinoline (5 g) in ethyl acetate (100 mL). Thereaction mixture was stirred at ambient temperature for 2 days. Theresulting precipitate was isolated by filtration, washed with hexane anddried to provide 3.4 g of 2-ethylthiazolo[4,5-c]quinoline-5N-oxide.

Part C

Trichloroacetyl isocyanate (6.5 mL, 54 mmol) was added to a suspensionof 2-ethylthiazolo[4,5-c]quinoline-5N-oxide (9.0 g, 39.1 mmol) indichloromethane (500 mL). The reaction mixture was stirred at ambienttemperature for 2 hours and then concentrated under vacuum to providecrude N-(2-ethylthiazolo[4,5-c]quinolin-4-yl)trichloroacetamide. Thismaterial was added to a solution of ammonia in methanol (500 mL of 2M)and stirred at ambient temperature for about 2 hours. The reactionmixture was concentrated under vacuum. The residue was taken up indichloromethane, washed with sodium bicarbonate (2×150 mL) then withwater (3×150 mL), dried over magnesium sulfate and then concentratedunder vacuum. The residue was recrystallized from 1,2-dichloroethane toprovide tan needles. This material was suspended in water; oneequivalent of concentrated hydrochloric acid was added and the mixturewas heated to dissolve the solids. The solution was treated withcharcoal and then filtered. The filtrate was cooled and then made basicwith sodium carbonate. The resulting precipitate was isolated byfiltration, washed with water and then recrystallized from1,2-dichloroethane to provide 2-ethylthiazolo[4,5-c]quinolin-4-amine asyellow needles, m.p. 169-171° C. Analysis: Calculated for C₁2H₁₁N₃S: %C,62.85; %H, 4.83; %N, 18.32; Found: %C, 62.79; %H, 4.86; %N, 18.22.

Example 10 2-Ethylthiazolo[4,5-c]quinolin-4-amine Hydrochloride

Concentrated hydrochloric acid (18.5 mmol) was added to a solution of2-ethylthiazolo[4,5-c]quinolin-4-amine (4.25 g) in warm isopropanol. Thereaction mixture was heated at reflux to reduce the volume and removethe water. The reaction mixture was cooled to ambient temperature. Theprecipitate was isolated by filtration and then dried to provide2-ethylthiazolo[4,5-c]quinolin-4-amine hydrochloride as a solid, m.p.268-270° C. Analysis: Calculated for C₁₂H₁₁N₃S.HCl: %C, 54.23; %H, 4.55;%N, 15.81; Found: %C, 54.25; %H, 4.63; %N, 15.71.

Example 11

Part A

Using the general method of Example 7 Part A,2-methylthiazolo[4,5-c]quinoline (2.50 g, 12.5 mmol) was reacted firstwith lithium diisopropylamide and then with ethyl iodide to provide 0.28g of 2-propylthiazolo[4,5-c]quinoline as a yellow crystalline solid,m.p. 54° C. Analysis: Calculated for C₁₃H₁₂N₂S: %C, 68.39; %H, 5.30; %N,12.27; Found: %C, 68.4 1; %H, 5.19; %N, 12.3 1.

Part B

Using the general method of Example 7 Part B,2-propylthiazolo[4,5-c]quinoline (1.05 g, 4.6 mmol) was oxidized with3-chloroperoxybenzoic acid to provide 0.65 g of2-propylthiazolo[4,5-c]quinoline-5N-oxide as a yellow solid, mp 123° C.Analysis: Calculated for C₁₃H₁₂N₂OS: %C, 63.91; %H, 4.95; %N, 11.47;Found: %C, 63.53; %H, 4.88; %N, 11.44.

Example 12

Using the general method of Example 8,2-propylthiazolo[4,5-c]quinoline-5N-oxide (0.63 g) was reacted withtrichloroacetyl isocyanate and the resulting amide intermediate washydrolyzed using a solution of ammonia in methanol to provide 0.22 g of2-propylthiazolo[4,5-c]quinolin-4-amine as a white crystalline solid,m.p. 140-142° C. Analysis: Calculated for C₁₃H₁₃N₃S: %C, 64.17; %H,5.38; %N, 17.27; Found: %C, 64.31; %H, 5.39; %N, 17.13.

Example 13 2-Propylthiazolo[4,5-c]quinolin-4-amine Alternative Synthesis

Part A

Using the general method of Example 9 Part A, a suspension of3-amino-quinoline-4-thiol (15 g) in butyric acid was reacted withbutyric anhydride to provide 2-propylthiazolo[4,5-c]quinoline as ayellow oil.

Part B

Using the general method of Example 9 Part B,2-propylthiazolo[4,5-c]quinoline (46 g) was oxidized with peracetic acidto provide 2-propylthiazolo[4,5-c]quinoline-5N-oxide as a yellowcrystalline solid.

Part C

Ammonium hydroxide (50 mL) was added to a solution of2-propylthiazolo[4,5-c]quinoline-5N-oxide (20 g) in chloroform (500 mL).The reaction mixture was cooled with an ice bath and then a solution oftosyl chloride (16 g) in chloroform was added dropwise. The reactionmixture was refluxed for 2 hours and then diluted with additionalchloroform and water. The layers were separated. The organic layer waswashed with aqueous sodium bicarbonate, dried over magnesium sulfate andthen concentrated under vacuum. The residue was recrystallized from1,2-dichloroethane to provide 2-propylthiazolo[4,5-c]quinolin-4-amine asa tan solid, m.p. 140-142° C. Analysis: Calculated for C₁₃H₁₃N₃S: %C,64.17; %H, 5.38; %N, 17.27; Found: %C, 64.10; %H, 5.47; %N, 17.29.

Example 14 2-Propylthiazolo[4,5-c]quinolin-4-amine Hydrochloride

Using the general method of Example 10,2-propylthiazolo[4,5-c]quinolin-4-amine (1.75 g) was reacted with 1equivalent of concentrated hydrochloric acid to provide2-propylthiazolo[4,5-c]quinolin-4-amine hydrochloride as an off-whitecrystalline solid, m.p. 234-237° C. Analysis: Calculated for C₁₃H₁₃N₃SHCl: %C, 55.81; %H, 5.04; %N, 15.02; Found: %C, 55.86; %H, 5.02; %N,14.99.

Example 15

Part A

Using the general method of Example 7 Part A,2-methylthiazolo[4,5-c]quinoline (2.0 g, 10 mmol) was reacted first withlithium diisopropylamide (5.5 mL of 2M in benzene) and then with1-iodobutane (1.8 mL) to provide 1.1 g of2-pentylthiazolo[4,5-c]quinoline as a yellow solid, m.p. 62-64° C.

Part B

Peracetic acid (1.50 mL of 32% in acetic acid) was added to a suspensionof 2-pentylthiazolo[4,5-c]quinoline (1.25 g) in methyl acetate (50 mL).The reaction mixture was heated at reflux for 6 hours. The reactionmixture was allowed to cool to ambient temperature and then it wasdiluted with dichloromethane and washed first with sodium bicarbonateand then with water. The organic layer was dried over magnesium sulfateand then concentrated under vacuum to provide 1.20 g of a pale yellowsolid. This material was recrystallized from ethyl acetate to provide0.90 g of 2-pentylthiazolo[4,5-c]quinoline-5N-oxide as a whitecrystalline solid, m.p. 142-144° C. Analysis: Calculated for C₁₅H₁₆N₂OS:%C, 66.14; %H, 5.92; %N, 10.19; Found: %C, 65.63; %H, 5.83; %N, 10.28.

Example 16

Trichloroacetyl isocyanate (0.51 mL) was added to a solution of2-pentylthiazolo[4,5-c]quinoline-5N-oxide (0.78 g) in dichloromethane(50 mL). The reaction mixture was stirred at ambient temperature forabout 75 minutes and then concentrated under vacuum to provide crudeN-(2-pentylthiazolo[4,5-c]quinolin-4-yl)trichloroacetamide. The amidewas combined with a solution of ammonia in methanol (40 mL of 2M).Dichloromethane was added to bring all of the material into solution.When the reaction was completed as indicated by thin layerchromatography, the reaction mixture was concentrated under vacuum. Theresidue was mixed with dichloromethane and sodium bicarbonate. Theorganic layer was separated, washed with sodium bicarbonate then withwater, dried over magnesium sulfate and then concentrated under vacuumto provide a white solid. This material was recrystallized from ethylacetate to provide 2-pentylthiazolo[4,5-c]quinolin-4-amine as anoff-white crystalline solid, m.p. 119-121° C. Analysis: Calculated forC₁₅H₁₇N₃S: %C, 66.39; %H, 6.31; %N, 15.48; Found: %C, 66.21; %H, 6.35;%N, 15.39.

Example 17

Part A

Using the general method of Example 7 Part A,2-methylthiazolo[4,5-c]quinoline (2.50 g, 12.5 mmol) was reacted firstwith lithium diisopropylamide (7.0 mL of 2M in benzene) and then with1-iodopropane (3.0 g) to provide 1.19 g of2-butylthiazolo[4,5-c]quinoline as a yellow oil.

Part B

Using the general method of Example 15 Part B,2-butylthiazolo[4,5-c]quinoline (1.33 g) was oxidized with peraceticacid to provide 0.5 g of 2-butylthiazolo[4,5-c]quinoline-5N-oxide as asolid, m.p. 133-135° C.

Example 18

Using the general method of Example 16,2-butylthiazolo[4,5-c]quinoline-5N-oxide (0.50 g) was converted to theamide and then hydrolyzed to provide 0.25 g of2-butylthiazolo[4,5-c]quinolin-4-amine as a yellow crystalline solid,m.p. 149-151° C. Analysis: Calculated for C₁₄H₁₅N₃S: %C, 65.34; %H,5.87; %N, 16.33; Found: %C, 64.88; %H, 5.84; %N, 16.03.

Example 19

Part A

Using the general method of Example 7 Part A,2-methylthiazolo[4,5-c]quinoline (1.50 g, 7.5 mmol) was reacted firstwith lithium diisopropylamide (15.0 mL of 2M in benzene) and then withmethyl iodide (2.4 mL) to provide 0.97 g of2-(1-methylethyl)Ithiazolo[4,5-c]quinoline as a yellow oil.

Part B

Using the general method of Example 15 Part B,2-(1-methylethyl)thiazolo[4,5-c]quinoline (0.95 g) was oxidized withperacetic acid to provide 0.84 g of2-(1-methylethyl)thiazolo[4,5-c]quinoline-5N-oxide as a yellow solid,m.p. 161-162° C.

Example 20

Using the general method of Example 16,2-(1-methylethyl)thiazolo[4,5-c]quinoline-5N-oxide (0.84 g) wasconverted to the amide and then hydrolyzed to provide 0.16 g of2-(1-methylethyl)thiazolo[4,5-c]quinolin-4-amine as yellow needles, m.p.163-165° C. Analysis: Calculated for C₁₃H₁₃N₃S: %C, 64.17; %H, 5.38; %N,17.27; Found: %C, 63.49; %H, 5.36; %N, 17.09.

Example 21

Part A

Using the general method of Example 7 Part A,2-methylthiazolo[4,5-c]quinoline (5.0 g, 25 mmol) was reacted first withlithium diisopropylamide (15.0 mL of 2M in benzene) and then withbenzaldehyde (3.8 mL) to provide 5.3 g1-phenyl-2-thiazolo[4,5-c]quinolin-2-yl-1-ethanol as a solid, m.p.147-148° C.

Part B

Concentrated hydrochloric acid was added dropwise to a suspension of1-phenyl-2-thiazolo[4,5-c]quinolin-2-yl-1-ethanol (2.16 g) in water (40mL) until all of the solid had dissolved. The reaction mixture washeated on a steam bath during the addition; heating was continued untilanalysis by thin layer chromatography indicated that all of the startingmaterial had reacted. The reaction mixture was allowed to cool toambient temperature and a precipitate formed. The reaction mixture wasneutralized with sodium carbonate. Dichloromethane was added withstirring until all of the precipitate was in solution. The layers wereseparated and the aqueous layer was extracted with dichloromethane. Theorganic layers were combined, washed with water, dried over magnesiumsulfate and then concentrated under vacuum to provide 2.2 g of a greensolid. This material was recrystallized from ethyl acetate to provide1.55 g of 2-(2-phenyl-1-ethenyl)thiazolo[4,5-c]quinoline as a greencrystalline solid. Analysis: Calculated for: C₁₈H₁₂N₂S: %C, 74.97; %H,4.19; %N, 9.71; Found: %C, 74.89; %H, 4.17; %N, 9.72.

Part C

Peracetic acid (1.32 mL of 32% in acetic acid) was added to a suspensionof 2-(2-phenyl-1-ethenyl)thiazolo[4,5-c]quinoline (1.20 g) in methylacetate (50 mL). A precipitate formed. Ethanol was added to the reactionmixture until all of the precipitate was dissolved. The reaction mixturewas heated at reflux overnight and then cooled to ambient temperature.The resulting precipitate was isolated by filtration, dried and thenrecrystallized from methanol/dichloromethane to provide2-(2-phenyl-1-ethenyl)thiazolo[4,5-c]quinoline-5N-oxide as a yellowsolid, m.p. 268-270° C. Analysis: Calculated for: C₁₈H₁₂N₂OS: %C, 71.03;%H, 3.97; %N, 9.20; Found: %C, 69.94; %H, 3.87; %N, 9.05.

Example 22

Using the general method of Example 16,2-(2-phenyl-1-ethenyl)thiazolo[4,5-c]quinoline-5N-oxide (0.67 g) wasconverted to the trichloroacetamide then hydrolyzed to provide 0.43 g of2-(2-phenyl-1-ethenyl)thiazolo[4,5-c]quinolin-4-amine as a yellowcrystalline solid, m.p. 239-241° C. Analysis: Calculated for C₁₈H₁₃N₃S:%C, 71.26; %H, 4.32; %N, 13.85; Found: %C, 70.73; %H, 4.15; %N, 13.68.

Example 23

Part A

A small amount of catalyst (5% palladium on activated carbon) was addedto a suspension of 2-(2-phenyl-1-ethenyl)thiazolo[4,5-c]quinoline (1.16g, Example 21 Part B) in acetic acid (200 mL). The mixture was reducedon a Parr apparatus under a 50 psi (3.5 Kg/cm²) hydrogen atmosphere for1 day. The reaction mixture was filtered to remove the catalyst. Thefiltrate was concentrated under vacuum. The residue was dissolved indichloromethane, washed with sodium bicarbonate then with water, driedover magnesium sulfate and then concentrated under vacuum to provide0.88 g of 2-(2-phenyl-1-ethyl)thiazolo[4,5-c]quinoline as an oily solid.

Part B

Using the general method of Example 15 Part B,2-phenylethylthiazolo[4,5-c]quinoline (0.90 g) was oxidized withperacetic acid to provide 0.63 g of2-(2-phenyl-1-ethyl)thiazolo[4,5-c]quinoline-5N-oxide as an orangecrystalline solid, m.p. 165-169° C. Analysis: Calculated for C₁₈H₁₄N₂OS:%C, 70.56; %H, 4.60; %N, 9.14; Found: %C, 69.59; %H, 4.50; %N, 9.04.

Example 24

Using the general method of Example 16,2-(2-phenyl-1-ethyl)thiazolo[4,5-c]quinoline-5N-oxide (0.63 g) wasconverted to the trichloroacetamide then hydrolyzed to provide 0.21 g of2-(2-phenyl-1 -ethyl)thiazolo[4,5-c]quinolin-4-amine as a yellowcrystalline solid, m.p. 158-159° C. Analysis: Calculated for C₁₈H₁₅N₃S:%C, 70.79; %H, 4.95; %N, 13.75; Found: %C, 70.29; %H, 4.90; %N, 13.66.

Example 25

Part A

Under an argon atmosphere, anhydrous tetrahydrofuran (150 mL) was addedto a dried flask containing 2-methylthiazolo[4,5-c]quinoline (8.40 g).The reaction mixture was cooled to −78° C. with a dry ice bath. Lithiumdiisopropylamide (23 mL of 2.0 M in benzene) was added dropwise. Afterabout 50 minutes, acetone (5 mL) was added and the reaction mixture wasallowed to warm to 0° C. After several hours the reaction was quenchedwith water, diluted with chloroform and then washed with water. Theorganic layer was dried over magnesium sulfate and then concentratedunder vacuum. The residue was suspended in water (200 mL) and themixture was heated. Hydrochloric acid (6N) was slowly added until all ofthe solid dissolved. Charcoal was added and the mixture was heated withstirring for about 5 minutes. The mixture was filtered to remove thecharcoal. The filtrate was neutralized with sodium carbonate and thenextracted with chloroform. The chloroform extract was washed severaltimes with water, dried over magnesium sulfate and then concentratedunder vacuum to provide 8.0 g of a light brown solid. This material wasrecrystallized from dichloromethane/hexanes to provide 5.0 g of2-methyl-1-(thiazolo[4,5-c]quinolin-2-yl)-2-propanol as a yellowcrystalline solid, m.p. 155-157° C. Analysis: Calculated for C₁₄H₁₄N₂OS:%C, 65.08; %H, 5.46; %N, 10.84; Found: %C, 64.97; %H, 5.33; %N, 10.90.

Part B

Peracetic acid (4.8 mL of 32% in acetic acid) was added to a suspensionof 2-methyl-1-(thiazolo[4,5-c]quinolin-2-yl)-2-propanol (3.0 g) inmethyl acetate (200 mL). The reaction mixture was heated at refluxovernight, cooled to ambient temperature and then concentrated undervacuum. The residue was dissolved in dichloromethane and then combinedwith sodium bicarbonate and stirred vigorously. The resultingprecipitate was isolated by filtration and then dissolved inmethanol/dichloromethane. This solution was concentrated under vacuum.The residue was combined with dichloromethane and then filtered toremove undissolved material. The filtrate was concentrated under vacuumto provide 2.6 g of the desired N-oxide. A small portion (0.2 g) wasrecrystallized from methanol/water to provide2-methyl-1-(thiazolo[4,5-c]quinolin-2-yl)-2-propanol-5N-oxide as asolid, m.p. 187-189° C. Analysis: Calculated for C₁₄H₁₄N₂O₂S. ⅓0 H₂O:%C, 59.98 %H, 5.27; %N, 9.99; Found: %C, 60.09; %H, 5.03; %N, 10.00.

Example 26

Trichloroacetyl isocyanate (3.2 mL was added to a solution of2-methyl-1-(thiazolo[4,5-c]quinolin-2-yl)-2-propanol-5N-oxide (2.4 g) indichloromethane (250 mL). The reaction mixture was stirred at ambienttemperature for 1 hour and then concentrated under vacuum. The residuewas stirred with a solution of ammonia in methanol (150 mL of 2M) for 2hours. The methanol was removed under vacuum. The residue was suspendedin a mixture of dichloromethane and ethyl acetate and then washed withsodium bicarbonate. The undissolved material was isolated by filtration,washed with water, washed with dichloromethane and then recrystallizedfrom methanol/dichloromethane to provide 1.6 g of2-(4-aminothiazolo[4,5-c]quinolin-2-yl)-1,1-dimethylethyl carbamate as asolid, m.p. 222-223° C. Analysis: Calculated for C₁₅H₁₆N₄O₂S: %C, 56.94;%H, 5.09; %N, 17.70; Found: %C, 56.71; %H, 5.08; %N, 17.52.

Example 27

Part A

Ethoxyacetyl chloride (6 mL, 53.8 mmol) was added to a suspension of3-aminoquinoline-4-thiol (4.6 g, 26.1 mmol) in ethoxyacetic acid (50mL). The reaction mixture was heated at 60° C. overnight. The reactionmixture was concentrated under vacuum to remove a portion of theethoxyacetic acid. The residue was combined with water (100 mL) and aprecipitate formed. The mixture was made basic with 50% sodiumhydroxide. The precipitate was isolated by filtration, washed with waterand then dried to provide 2-(ethoxymethyl)thiazolo[4,5-c]quinoline as afluffy green solid.

Part B

Peracetic acid (1.0 mL of 32% in acetic acid) was added to a solution of2-(ethoxymethyl)thiazolo[4,5-c]quinoline (1.0 g) in ethanol. Thereaction mixture was stirred at ambient temperature for 1 week. Thereaction mixture was concentrated under vacuum and then azeotroped withheptane to remove acetic acid. The residue was dissolved indichloromethane, washed with sodium bicarbonate, washed with water,dried over magnesium sulfate and then concentrated under vacuum. Theresidue was recrystallized from isopropanol to provide2-(ethoxymethyl)thiazolo[4,5-c]quinoline-5N-oxide as a yellowcrystalline solid, m.p. 138-140° C. Analysis: Calculated forC₁₃H₁₂N₂O₂S: %C, 59.98; %H, 4.65; %N, 10.76; Found: %C, 59.85; %H, 4.66;%N, 10.71.

Example 28

Trichloroacetyl isocyanate (0.7 mL) was added to a solution of2-(ethoxymethyl)thiazolo[4,5-c]quinoline-5N-oxide (1.0 g) indichloromethane (50 mL). The reaction mixture was stirred at ambienttemperature for 2 hours and then concentrated under vacuum to provideN-(2-(ethoxymethyl)thiazolo[4,5-c]quinolin-4-yl)trichloroacetamide. Theamide was taken up in methanol and then combined with 1 equivalent ofsodium methoxide. The reaction mixture was stirred at ambienttemperature for 30 minutes and then concentrated under vacuum. Thereaction was run a second time using 2 g of the N-oxide. The productswere combined and recrystallized from isopropanol to provide 2.25 g of2-(ethoxymethyl)thiazolo[4,5-c]quinoline-4-amine as light yellowneedles, m.p. 149-151° C. Analysis: Calculated for C₁₃H₁₃N₃OS: %C,60.21; %H, 5.05; %N, 16.20; Found: %C, 59.86; %H, 4.97; %N, 16.16.

Example 29

Part A

Methoxyacetyl chloride (1.8 mL) was added to a mixture of3-aminoquinoline-4-thiol (2.8 g) in methoxyacetic acid (15 mL). Thereaction was heated at about 140° C. for 1 hour and then allowed to coolto ambient temperature. The reaction mixture was diluted with a smallamount of water, made basic with 10% sodium hydroxide and then extractedwith dichloromethane (300 mL). The extract was washed with sodiumbicarbonate, washed with water, dried over magnesium sulfate and thenconcentrated under vacuum to provide crude product as a dark oil. Theoil was dissolved in dichloromethane and then placed on a layer ofsilica gel. The silica gel was eluted with 1:1 hexane:ethyl acetate. Theeluant was concentrated under vacuum to provide 2.3 g of2-(methoxymethyl)thiazolo[4,5-c]quinoline as an orange solid.

Part B

Using the general method of Example 27 Part B,2-(methoxymethyl)thiazolo[4,5-c]quinoline (1.7 g) was oxidized toprovide 1.8 g of 2-(methoxymethyl)thiazolo[4,5-c]quinoline-5N-oxide asyellow needles, m.p. 151-153° C. Analysis: Calculated for C₁₂H₁₀N₂OS:%C, 58.52; %H, 4.09; %N, 11.37; Found: %C, 57.95; %H, 3.98; %N, 11.3.

Example 30

Using the general method of Example 28,2-(methoxymethyl)thiazolo[4,5-c]quinoline-5N-oxide (1.3 g) was reactedto form the trichloroacetamide and then hydrolyzed to provide2-(methoxymethyl)thiazolo[4,5-c]quinolin-4-amine as light yellowneedles, m.p. 183-185° C. Analysis: Calculated for C₁₂H₁₁N₃OS: %C,58.76; %H, 4.52; %N, 17.13; Found: %C, 58.69; %H, 4.34; %N, 17.14.

Example 31

Part A

3-Amininoquinoline-4-thiol (4.6 g) was added to polyphosphoric acid (80g). Isovaleric acid (3.5 mL) was added and the reaction mixture washeated at 140° C. for 2 hours. The reaction mixture was poured into amixture of ice and water (300 mL). The mixture was filtered through alayer of Celite® filter aid to remove some insoluble material. Thefiltrate was made alkaline with 50% sodium hydroxide while cooling withice and then extracted with chloroform. The extract was washed withwater, dried over magnesium sulfate and then concentrated under vacuumto provide an oil. The oil was dissolved in dichloromethane and thenplaced on a layer of silica gel and eluted with 1:1 ethylacetate:hexanes. The eluant was concentrated under vacuum to provide2-(2-methylpropyl)thiazolo[4,5-c]quinoline.

Part B

Using the general method of Example 27 Part B,2-(2-methylpropyl)thiazolo[4,5-c]quinoline (5.2 g) was oxidized toprovide 2.5 g of 2-(2-methylpropyl)thiazolo[4,5-c]quinoline-5N-oxide asa yellow solid.

Example 32

Using the general method of Example 28,2-(2-methylpropyl)thiazolo[4,5-c]quinoline-5N-oxide (2.5 g) was reactedto form the trichloroacetamide and then hydrolyzed to provide2-(2-methylpropyl)thiazolo[4,5-c]quinolin-4-amine as light yellowplatelets, m.p. 123-125° C. Analysis: Calculated for C₁₄H₁₅N₃S: %C,65.34; %H, 5.87; %N, 16.33; Found: %C, 64.87; %H, 5.79; %N, 16.18.

Example 33

Part A

Thionyl chloride (1.5 g) was added dropwise to a cooled solution ofphenyl acetic acid (2 g) in dichloromethane (10 mL). This mixture wasallowed to stir at ambient temperature for 1 hour to provide a solutioncontaining phenylacetyl chloride. Triethyl amine (4.3 mL) was added to asuspension of 3-aminoquinolin-4-ol in dichloromethane (10 mL) and theresulting mixture was cooled in an ice bath. The phenylacetyl chloridesolution was added dropwise to the cooled mixture. The reaction mixturewas allowed to stir at ambient temperature overnight. The resultingthick oily precipitate was diluted with water (10 mL) and then stirredrapidly for 1 hour. The reaction mixture was filtered. Thin layerchromatography showed that both the isolated solid and the filtratecontained the desired product. The filtrate was diluted withdichloromethane and water. The dichloromethane layer was separated,dried over magnesium sulfate and then concentrated under vacuum. Theresidue was combined with the previously isolated solid andrecrystallized from 80:20 isopropanol:water to provide 1.3 g ofN-(4-hydroxyquinolin-3-yl)phenylacetamide as needles, m.p. 253-255° C.Analysis: Calculated for: C₁₇H₁₄N₂O₂: %C, 73.37; %H, 5.07; %N, 10.07;Found: %C, 73.16; %H, 5.03; %N, 10.07.

Part B

Phosphorous pentasulfide (1.6 g) was added to a suspension ofN-(4-hydroxyquinolin-3-yl)phenylacetamide (1.0 g) in pyridine. Thereaction mixture was heated at reflux until the reaction was complete.The reaction mixture was concentrated under vacuum and then azeotropedwith water to remove most of the pyridine. The residue was combined withwater, neutralized with sodium carbonate and then extracted withdichloromethane. The extract was washed with water, dried over magnesiumsulfate and then concentrated under vacuum to provide2-benzylthiazolo[4,5-c]quinoline as a solid.

Part C

Using the general method of Example 27 Part B,2-benzylthiazolo[4,5-c]quinoline (3.3 g) was oxidized to provide 2.1 gof 2-benzylthiazolo[4,5-c]quinoline-5N-oxide as a yellow solid, m.p.185-186° C. Analysis: Calculated for C₁₇H₁₂N₂OS: %C, 69.84; %H, 4.14;%N, 9.58; Found: %C, 69.51; %H, 4.06; %N, 9.55.

Example 34

Trichloroacetyl isocyanate (1.2 mL, 10.3 mmol) was added to a solutionof 2-benzylthiazolo[4,5-c]quinoline-5N-oxide (2.0 g, 6.8 mmol) indichloromethane (100 mL). The reaction mixture was stirred at ambienttemperature for 2 hours and then concentrated to provide crudeN-(2-benzylthiazolo[4,5-c]quinolin-4-yl)trichloroacetamide. The amidewas dissolved in methanol. Sodium methoxide (1 equivalent) was added.The reaction mixture was heated on a steam bath for 30 minutes and thenallowed to cool to ambient temperature. The resulting precipitate wasisolated by filtration and then suspended in a mixture of methanol andisopropanol. Hydrochloric acid (1 equivalent) was added and all of thesolid dissolved initially. A white solid crystallized out. This materialwas isolated by filtration, washed with isopropanol and then dried toprovide 1.5 g of 2-benzylthiazolo[4,5-c]quinolin-4-amine hydrochloride,m.p. 152-155° C. Analysis: Calculated for: C₁₇H₁₃N₃S.HCl: %C, 62.28; %H,4.30; %N, 12.82; Found: %C, 62.05; %H, 4.23; %N, 12.82.

Example 35

Part A

Catalyst (0.10 g of 10% platinum on carbon) was added to a solution of6-methyl-3-nitroquinolin-4-ol (1 g) in ethanol (25 mL) and ammoniumhydroxide (0.5 mL). The mixture was reduced on a Parr apparatus atambient temperature under a hydrogen atmosphere. The reaction mixturewas filtered to remove the catalyst and then concentrated under vacuum.The residue was combined with water and heated. Hydrochloric acid wasadded dropwise until all of the solid had dissolved. Activated carbonwas added to the solution. The mixture was filtered. Hydrochloric acid(2 mL of 12N) was added to the filtrate. This recrystallization was runthree times to provide 0.50 g of 3 -amino-6-methylquinolin-4-olhydrochloride, m.p.>310° C. Analysis: Calculated for C₁₀H₁₀N₂O.HCl: %C,57.02; %H, 5.26; %N, 13.30; Found: %C, 56.92; %H, 5.16; %N, 13.24.

Part B

Triethylamine (11.46 mL) was added to a suspension of3-amino-6-methylquinolin-4-ol hydrochloride in dichloromethane (400 mL).Butyryl chloride (4.46 mL) was added. The reaction mixture was heated ona steam bath for 30 minutes. The solution was diluted with sodiumbicarbonate and then filtered. The filtrate was washed with bicarbonateand then concentrated under vacuum. The residue was recrystallized fromisopropanol to provide 3-butyramido-6-methylquinolin-4-ol hemihydrate asa solid, m.p. 274-277° C. Analysis: Calculated for C₁₄H₁₆N₂O₂.½ H₂O: %C,66.39; %H, 6.76; %N, 11.06; Found: %C, 66.56; %H, 6.46; %N, 11.03.

Part C

Phosphorous pentasulfide (12.9 g) was added to a mixture of3-butyramido-6-methylquinolin-4-ol hemihydrate (7.12 g) in pyridine. Thereaction mixture was heated at reflux for 90 minutes, combined with amixture of ice and sodium carbonate and then extracted withdichloromethane. The extract was concentrated under vacuum. The residuewas diluted with toluene and then concentrated under vacuum to provide acrude solid. This material was purified using column chromatographyeluting with 20% dichloromethane in ethyl acetate to provide8-methyl-2-propylthiazolo[4,5-c]quinoline as a yellow solid.

Part D

Using the general method of Example 7 Part B,8-methyl-2-propylthiazolo[4,5-c]quinoline (4.0 g) was oxidized using3-chloroperoxybenzoic acid to provide 4.19 g of crude product which wasrecrystallized from isopropanol to provide 2.0 g of8-methyl-2-propylthiazolo[4,5-c]quinoline-5N-oxide as a solid, m.p.143-145° C. Analysis: Calculated for C₁₄H₁₄N₂OS: %C, 65.09; %H, 5.46;%N, 10.84; Found: %C, 64.86; %H, 5.40; %N, 10.88.

Example 36

Using the general method of Example 28,8-methyl-2-propylthiazolo[4,5-c]quinoline-5N-oxide was converted toN-(8-methyl-2-propylthiazolo[4,5-c]quinolin-4-yl)trichloroacetamide andthen hydrolyzed to provide 1.32 g of8-methyl-2-propylthiazolo[4,5-c]quinolin-4-amine as a crystalline solid,m.p. 147-149° C. Analysis: Calculated for C₁₄H₁₅N₃S: %C, 63.54; %H,5.87; %N, 16.33; Found: %C, 64.97; %H, 5.76; %N, 16.25.

Example 37

Part A

Triethylamine (7.3 mL) was added to a suspension of 3-aminoquinolin-4-ol(5 g) in dichloromethane (50 mL). The mixture was cooled in an ice bathand then acetoxyacetyl chloride (3 mL) was added dropwise. The reactionmixture was stirred at ambient temperature for 2 hours. The resultingthick precipitate was diluted with water (10 mL), stirred rapidly for 20minutes and then isolated by filtration. Thin layer chromatographyindicated that both the solid and the filtrate contained the desiredproduct. The filtrate was concentrated under vacuum. The residue wasmixed with water and then filtered. The combined solids wererecrystallized from 80:20 isopropanol:water to provideN-(4-hydroxyquinolin-3-yl)acetoxyacetamide, m.p. 224-225° C.

Part B

Using the general method of Example 33 Part B,N-(4-hydroxyquinolin-3-yl)acetoxyacetamide (5.3 g) was reacted withphosphorous pentasulfide to provide 2.9 g ofthiazolo[4,5-c]quinolin-2-ylmethyl acetate as a solid.

Part C

Using the general method of Example 27 Part B,thiazolo[4,5-c]quinolin-2-ylmethyl acetate (2.8 g) was oxidized withperacetic acid to provide thiazolo[4,5-c]quinolin-2-ylmethylacetate-5N-oxide as a tan crystalline solid.

Part D

Trichloroacetyl isocyanate (0.65 mL) was added to a solution ofthiazolo[4,5-c]quinolin-2-ylmethyl acetate-5N-oxide (1.0 g) indichloromethane (50 mL). The reaction was stirred at ambient temperaturefor 2 hours and then concentrated under vacuum. The residue wasdissolved in methanol. Sodium methoxide (1 equivalent) was added and thereaction mixture was stirred at ambient temperature overnight. Theresulting precipitate was isolated by filtration and dried to provide0.68 g of (4-aminothiazolo[4,5-c]quinolin-2-yl)methanol as a whitesolid, m.p. 247-249° C. Analysis: Calculated for C₁₁H₉N₃OS: %C, 57.13;%H, 3.92; %N, 18.17; Found: %C, 56.85; %H, 3.96; %N, 17.83.

Example 38

Part A

3-Aminoquinolin-4-ol (6 g) was refluxed with acetic anhydride (8 eq.)until analysis by thin layer chromatography indicated that the reactionwas complete. The reaction mixture was cooled, diluted with ice andwater, made basic with 10% sodium hydroxide and then extracted withdichloromethane. The extract was washed with water and brine, dried overmagnesium sulfate and then concentrated under vacuum. The residue waspurified by column chromatography (silica gel eluting withmethanol/ethyl acetate) to provide 5.1 g of2-methyloxazolo[4,5-c]quinoline.

Part B

A mixture of 2-methyloxazolo[4,5-c]quinoline (5.0 g), peracetic acid (5eq.) and ethanol was stirred at ambient temperature. After 2 hours moreperacetic acid (2 eq) was added and stirring was continued for 3additional hours. The reaction mixture was concentrated under vacuum.The residue was azeotroped with heptane to provide 4.2 g of2-methyloxazolo[4,5-c]quinoline-5N-oxide.

Part C

Trichloroacetyl isocyanate (3.6 mL) was slowly added to a cooled mixtureof 2-methyloxazolo[4,5-c]quinoline-5N-oxide (4.0 g) and dichloromethane.The reaction mixture was stirred for several hours and then concentratedunder vacuum to provide crudeN-(2-methyloxazolo[4,5-c]quinolin-4-yl)trichloroacetamide. This materialwas combined with a solution of ammonia in methanol (2M) and stirred for1 hour. The reaction mixture was concentrated under vacuum, diluted withwater and then extracted with dichloromethane. The extract was washedwith water and brine, dried over magnesium sulfate and then concentratedunder vacuum. The residue was purified by column chromatography (silicagel eluting with ethyl acetate/hexane) to provide 1.2 g of2-methyloxazolo[4,5-c]quinolin-4-amine as a solid, m.p. 195-197° C.Analysis: Calculated for C₁₁H₉N₃O: %C, 66.32; %H, 4.55; %N, 21.09;Found: %C, 65.96; %H, 4.44; %N, 20.68.

Example 39

Part A

3-Aminoquinolin-4-ol hydrochloride (6 g) was refluxed with propanoicanhydride (8 eq.) until analysis by thin layer chromatography indicatedthat the reaction was complete. The reaction mixture was cooled, dilutedwith ice and water, made basic with 10% sodium hydroxide and thenextracted with dichloromethane. The extract was washed with water andbrine, dried over magnesium sulfate and then concentrated under vacuum.The residue was purified by column chromatography (silica gel elutingwith methanol/ethyl acetate) to provide 4.0 g of2-ethyloxazolo[4,5-c]quinoline.

Part B

2-Ethyloxazolo[4,5-c]quinoline (3.5 g), peracetic acid (4.5 mL of 32% inacetic acid) and methyl acetate (40 mL) were combined and heated at 50°C. for several hours. The reaction mixture was concentrated undervacuum. The residue was slurried with hexane and then filtered toprovide 2.5 g of 2-ethyloxazolo[4,5-c]quinoline-5N-oxide as a solid.

Part C

Trichloroacetyl isocyanate (2 mL) was slowly added to a cooled mixtureof 2-ethyloxazolo[4,5-c]quinoline-5N-oxide (2.5 g) and dichloromethane.The reaction mixture was stirred for several hours and then concentratedunder vacuum to provide crudeN-(2-ethyloxazolo[4,5-c]quinolin-4-yl)trichloroacetamide. This materialwas combined with a solution of ammonia in methanol (2M) and stirred for1 hour. The reaction mixture was concentrated under vacuum, diluted withwater and then extracted with dichloromethane. The extract was washedwith water and brine, dried over magnesium sulfate and then concentratedunder vacuum. The residue was purified by column chromatography (silicagel eluting with ethyl acetate/hexane) to provide2-ethyloxazolo[4,5-c]quinolin-4-amine as a solid, m.p. 175-178° C.Analysis: Calculated for C₁₂H₁₁N₃O: %C, 67.59; %H, 5.20; %N, 19.71;Found: %C, 67.19; %H, 4.86; %N, 20.43.

Example 40

Part A

3-Aminoquinolin-4-ol hydrochloride (1.97 g, 10.0 mmol), triethylamine(1.01 g, 10.1 mmol) and valeric anhydride (9.3 g, 50.0 mmol) werecombined and then heated at reflux for 18 hours. The reaction mixturewas cooled to ambient temperature and then poured over ice. The mixturewas adjusted to pH 12 with 10% sodium hydroxide. The mixture was stirreduntil all of the ice melted and then it was extracted with diethylether. The ether extracts were combined, dried over magnesium sulfateand then concentrated under vacuum to provide a tan solid. This materialwas purified by flash chromatography eluting with 3:2 ethylacetate:dichloromethane to provide 1.45 g of2-butyloxazolo[4,5-c]quinoline.

Part B

Peracetic acid (1.6 g, 6.8 mmol of 32% in acetic acid) was added withstirring to a solution of 2-butyloxazolo[4,5-c]quinoline (1.4 g, 6.2mmol) in ethanol (50 mL). The reaction mixture was stirred at ambienttemperature for 3 days and then quenched with saturated potassiumcarbonate solution. The layers were separated. The organic layer wasconcentrated under vacuum to provide a tan solid. This material wasslurried with diethyl ether and then filtered to provide 0.6 g of2-butyloxazolo[4,5-c]quinolin-5N-oxide, m.p. 120-121° C. Analysis:Calculated for C₁₄H₁₄N₂O₂: %C, 69.41; %H, 5.82; %N, 11.56; Found: %C,69.22; %H, 5.76; %N, 11.59.

Example 41

Under a nitrogen atmosphere, trichloroacetyl isocyanate (0.6 g, 3.40mmol) was added with stirring to a solution of2-butyloxazolo[4,5-c]quinolin-5N-oxide (0.55 g, 2.27 mmol) in anhydrousdichloromethane (20 mL). The reaction mixture was maintained at ambienttemperature for 2 hours and then concentrated under vacuum to providecrude N-(2-butyloxazolo[4,5-c]quinolin-4-yl)trichloroacetamide as anoil. The oil was taken up in methanol (25 mL). Sodium methoxide (0.49 gof 25%, 2.27 mmol) was added to the solution. The reaction mixture washeated at reflux for 2 hours and then concentrated under vacuum. Theresidue was taken up in ethyl acetate and washed with water. The ethylacetate layer was concentrated under vacuum to provide an orange solid.This material was purified twice using flash chromatography eluting withethyl acetate the first time and with 30% dichloromethane in ethylacetate the second time to provide 0.15 g of2-butyloxazolo[4,5-c]quinolin-4-amine, m.p. 96-98° C. Analysis:Calculated for C₁₄H₁₅N₃O: %C, 69.69; %H, 6.27; %N, 17.41; Found: %C,69.23; %H, 6.06; %N, 17.07.

Example 42

Part A

Potassium nitrate (0.46 g, 4.52 mmol) was added to a solution of2-propylthiazolo[4,5-c]quinolin-4-amine (1 g, 4.11 mmol, Example 12) insulfuric acid (10 mL). The reaction mixture was stirred at ambienttemperature for 30 minutes, then poured onto ice, neutralized (pH=7)with ammonium hydroxide (150 mL) and then extracted withdichloromethane. The extract was washed with sodium bicarbonate, driedover magnesium sulfate and then concentrated under vacuum to provide 1 gof a yellow solid. This material was recrystallized fromisopropanol/water to provide 0.84 g of8-nitro-2-propylthiazolo[4,5-c]quinoline as a yellow solid, m.p.228-230° C. Analysis: Calculated for C₁₃H₁₂N₄O₂S: %C, 54.15; %H, 4.20;%N, 19.43; Found: %C, 54.22; %H, 4.05; %N, 19.04.

Part B

Catalyst (0.13 g of palladium on carbon) was added to a solution of8-nitro-2-propylthiazolo[4,5-c]quinoline (1.31 g) in ethanol. Themixture was reduced on a Parr apparatus under a hydrogen atmosphere. Thereaction mixture was filtered to remove catalyst and the filter cake waswashed with additional ethanol. The filtrate was concentrated undervacuum at 50° C. and then oven dried under nitrogen to provide2-propylthiazolo[4,5-c]quinolin-4,8-diamine as a yellow crystallinesolid, m.p. 190-192° C., Analysis: Calculated for C₁₃H₁₄N₄S: %C, 60.44;%H, 5.46; %N, 21.69; Found: %C, 60.11; %H, 5.45; %N, 21.96.

Example 43

Part A

A mixture of 3-aminoquinolin-4-ol hydrochloride (1.97 g, 10.0 mmol),butyric anhydride (3.15 g, 20 mmol) and pyridine (25 mL) was heated atreflux overnight. The reaction mixture was cooled and then poured overice. The mixture was made basic (pH 11) with 1 N sodium hydroxide andthen it was extracted with diethyl ether (3×100 mL). A precipitate wasremoved by filtration. The ether extracts were combined, dried overmagnesium sulfate and then concentrated to provide 1.1 g of2-propyloxazolo[4,5-c]quinoline as an off white solid.

Part B

3-Chloroperoxybenzoic acid (1.0 eq. of 60%) was added with stirring to asolution of 2-propyloxazolo[4,5-c]quinoline (1.0 g, 4.7 mmol) inchloroform (30 mL). The reaction mixture was stirred at ambienttemperature overnight and then quenched with a saturated potassiumcarbonate solution. The layers were separated. The aqueous layer wasextracted with dichloromethane. The organic layers were combined andconcentrated. The resulting crude product was purified by flashchromatography eluting with 8:2 ethyl acetate:dichloromethane to provide1.0 g of 2-propyloxazolo[4,5-c]quinoline-5N-oxide as a tan solid.

Part C

Trichloroacetyl isocyanate (0.9 g, 5.25 mmol) was added with stirring toa solution of 2-propyloxazolo[4,5-c]quinoline-5N-oxide (0.8 g, 3.5 mmol)in dichloromethane (30 mL). The reaction mixture was stirred at ambienttemperature for 2.5 hours and then concentrated under vacuum to providecrude N-(2-propyloxazolo[4,5-c]quinolin-4-yl)trichloroacetamide. Theamide was dissolved in methanol (50 mL) and then combined with sodiummethoxide (1.0 eq of 25% in methanol) and heated at reflux for 2 hours.The reaction mixture was concentrated under vacuum. The residue wastaken up in diethyl ether and water. The ether layer was separated andconcentrated to provide a tan solid. This material was purified by flashchromatography using two columns (The first was eluted with 8:2 ethylacetate:dichloromethane; the second with 1:1 ethylacetate:dichloromethane.) to provide 0.1 g of2-propyloxazolo[4,5-c]quinolin-4-amine as a yellow powder, m.p.159.0-160.0° C. Analysis: Calculated for C₁₃H₁₃N₃O: %C, 68.71; %H, 5.77;%N, 18.49; Found: %C, 68.03; %H, 5.77; %N, 18.14.

Example 44

2-Propylthiazolo[4,5-c]quinolin-4-amine (1.0 g, 0.41 mmol) was combinedwith acetic acid (15 mL) and heated to 60° C. Bromine (0.10 mL, 1.94mmol) was added dropwise and the reaction mixture was stirred at 60° C.for 18 hours. The reaction mixture was diluted with water and theresulting precipitate was isolated by filtration to provide 0.25 g of8-bromo-2-propylthiazolo[4,5-c]quinolin-4-amine as a yellow solid, m.p.177-180° C. Analysis: Calculated for C₁₃H₁₂BrN₃S: %C, 48.46; %H, 3.75;%N, 13.04; Found: %C, 47.98; %H, 3.95; %N, 12.70.

Example 45

Part A

Diethyl ethoxymethylmalonate (37.8 mL, 187 mmol) and m-toluidine (20.0mL, 187 mmol) were combined and heated at 100° C. for about 3 hours. Thereaction mixture was allowed to cool to ambient temperature and itsolidified. Dowtherm A (350 mL) was added and the reaction mixture washeated at reflux for about 30 minutes. The reaction mixture was allowedto cool to ambient temperature. The resulting precipitate was isolatedby filtration, rinsed with acetone and dried to provide 33 g of ethyl4-hydroxy-7-methyl-3-quinolinecarboxylate as a tan powder.

Part B

Ethyl 4-hydroxy-7-methyl-3-quinolinecarboxylate (32 g, 138 mmol) wassuspended in sodium hydroxide (500 mL of 10% aqueous) and then heated atreflux for about 30 minutes. The reaction mixture was allowed to cool toambient temperature and then it was acidified with concentratedhydrochloric acid. The resulting precipitate was isolated by filtration,rinsed well with water and then oven dried to provide4-hydroxy-7-methyl-3-quinolinecarboxylic acid (28 g). A portion (2 g)was recrystallized twice from N,N-dimethylformamide to give a fluffywhite solid, m.p. 264-265° C. Analysis: Calculated for C₁₁H₉NO₃: %C,65.02; %H, 4.46; %N, 6.89; Found: %C, 65.22; %H, 4.42; %N, 6.88.

Part C

4-Hydroxy-7-methyl-3-quinolinecarboxylic acid (32 g) was placed in around bottom flask and then heated in a Wood's metal bath at 310° C. forseveral minutes until all of the solids had melted into a light brownviscous liquid and bubbling had nearly ceased. The reaction mixture wasallowed to cool to ambient temperature. The crude solid wasrecrystallized from ethyl acetate/ethanol to give 9.8 g of7-methyl-4-quinolinol. During the recrystallization a portion of thesolid did not dissolve, this material was isolated by filtration andthen recrystallized to provide 1.1 g of 7-methyl-4-quinolinol asyellow-tan plates, m.p. 233-235° C. Analysis: Calculated for C₁₀H₉NO:%C, 75.45; %H, 5.70; %N, 8.80; Found: %C, 75.23; %H, 5.54; %N, 8.76.

Part D

Nitric acid (6 mL of 70%) was slowly added to a hot (125° C.) solutionof 7-methyl-4-quinolinol (10.5 g) in propionic acid (125 mL). Thereaction mixture was stirred for about 1.5 hours and then it was allowedto cool to ambient temperature. The resulting precipitate was isolatedby filtration, rinsed well with ethanol and water and then dried toprovide 6.9 g of 7-methyl-3-nitro-4-quinolinol as a pale yellow solid.

Part E

7-Methyl-3-nitro-4-quinolinol (11.8 g, 58 mmol), methanol (about 300mL), ammonium hydroxide (50 mL), and palladium on carbon (1 g of 10%)were combined. The mixture was placed on a Parr apparatus under a 35-40psi (2.4-2.8 Kg/cm²) hydrogen atmosphere for about 1 hour. The reactionmixture was filtered through a layer of Celite® filter agent and thefilter cake was rinsed well with methanol. The filtrate was treated withcharcoal and then concentrated under vacuum to provide a fluffy palegreen solid. This material was triturated with acetonitrile to provide8.5 g of 3-amino-7-methyl-4-quinolinol.

Part F

Under a nitrogen atmosphere, triethylamine (0.71 mL, 5.1 mmol) was addedto a suspension of 3-amino-7-methyl-4-quinolinol (800 mg, 4.6 mmol) indichloromethane (30 mL). Butyryl chloride (0.53 mL, 5.1 mmol) was added.The reaction mixture was stirred at ambient temperature for about 2hours. Analysis by thin layer chromatography (silica gel eluting with9:1 dichloromethane:methanol) showed starting material. The reactionmixture was heated to reflux and then inadvertently allowed to go dryover the course of about 30 minutes. More solvent was added and thereaction mixture was heated at reflux for an additional hour at whichtime thin layer chromatography showed no starting material. Theresulting precipitate was isolated by filtration and then rinsed withdichloromethane and water to provide 650 mg ofN-(4-hydroxy-7-methylquinolin-4-yl)butyramide as a pale pink-tan solid.

Part G

Under a nitrogen atmosphere, phosphorus pentasulfide (1.15 g, 2.6 mmol)was added to a mixture of N-(4-hydroxy-7-methylquinolin-4-yl)butyramide(630 mg, 2.6 mmol) in pyridine (20 mL). The reaction mixture was heatedto reflux. The reaction mixture turned bright yellow and all of thesolid went into solution. The reaction mixture was heated at reflux forabout 2 hours and then allowed to cool to ambient temperature. Thereaction mixture was extracted with water, aqueous sodium bicarbonateand dichloromethane. The organic layer was treated with saturated coppersulfate, dried with magnesium sulfate and then concentrated under vacuumto provide an oil. The oil was dried under high vacuum to provide 410 mgof 7-methyl-2-propylthiazolo[4,5-c]quinoline as an orange solid.

Part H

3-Chloroperoxybenzoic acid (2.4 g of 57-86%) was added to a mixture of7-methyl-2-propylthiazolo[4,5-c]quinoline (2 g) and chloroform (100 mL).The reaction mixture was allowed to stir at ambient temperature for 2hours. Analysis by thin layer chromatography showed no starting materialbut did show two products. The reaction mixture was stirred at ambienttemperature for an additional hour and then it was extracted withdichloromethane and aqueous sodium bicarbonate. The organic layer wasdried with magnesium sulfate and then concentrated under vacuum toprovide a yellow-orange oil. The oil was dried under high vacuum toprovide 2.1 g of 7-methyl-2-propylthiazolo[4,5-c]quinolin-5N-oxide as asolid.

Part I

Under a nitrogen atmosphere, trichloroacetyl isocyanate (1.4 mL, 12.1mmol) was added to a mixture of7-methyl-2-propylthiazolo[4,5-c]quinolin-5N-oxide (2.1 g, 8.1 mmol) anddichloromethane (100 mL). The resulting dark brown solution was allowedto stir at ambient temperature for about 2 hours. The reaction mixturewas concentrated under vacuum to provideN-(7methyl-2-propylthiazolo[4,5-c}quinolin-4-yl)trichloroacetamide as anoil. The oil was combined with methanol and sodium methoxide (1.9 mL of25% in methanol, 8.1 mmol) and then stirred at ambient temperature for 1hour. The resulting precipitate was isolated by filtration and thenrecrystallized twice from isopropanol to provide 500 mg of7-methyl-2-propylthiazolo[4,5-c]quinolin-4-amine as a yellow-tan powder,m.p. 186-187° C. Analysis: Calculated for C₁₄H₁₅N₃S: %C, 65.34; %H,5.87; %N, 16.33; Found: %C, 64.95; %H, 5.77; %N, 16.08.

Example 46

Part A

Under a nitrogen atmosphere, a mixture of 3-amino-7-methyl-4-quinolinol(5 g, 28.7 mmol) and valeric anhydride (28 mL, 143.5 mmol) was heated atreflux for about 20 hours. The reaction mixture was allowed to cool toambient temperature, then it was made basic with 10% sodium hydroxideand stirred for an additional hour at ambient temperature. The reactionmixture was extracted with dichloromethane. The extract was dried overmagnesium sulfate and then concentrated under vacuum to provide a darkbrown liquid. The liquid was purified by column chromatography (silicagel eluting with 3:2 ethyl acetate:dichloromethane) to provide 4.7 g ofa dark brown, semi-solid. A portion (about 700 mg) was purified bycolumn chromatography (silica gel eluting with 95:5dichloromethane:methanol) to provide2-butyl-7-methyloxazolo[4,5-c]quinoline, m.p. 52-55° C. Analysis:Calculated for C₁₅H₁₆N₂O: %C, 74.97; %H, 6.71; %N, 11.66; Found: %C,74.80; %H, 6.73; %N, 11.53.

Part B

3-Chloroperoxybenzoic acid (4.6 g of 57-86%) was added to a solution of2-butyl-7-methyloxazolo[4,5-c]quinoline (3.9 g, 16.2 mmol) in chloroform(100 mL). The reaction mixture was allowed to stir at ambienttemperature for 4 hours. The reaction mixture was washed with aqueoussodium bicarbonate, dried over magnesium sulfate and then concentratedunder vacuum to provide 4.2 g of2-butyl-7-methyloxazolo[4,5-c]quinolin-5N-oxide as a dark brown-orangeoil.

Part C

Under a nitrogen atmosphere, trichloroacetyl isocyanate (2.9 mL, 24mmol) was added to a mixture of2-butyl-7-methyloxazolo[4,5-c]quinolin-5N-oxide (4.2 g, 16 mmol) anddichloromethane (100 mL). The reaction mixture was allowed to stir atambient temperature for about 3 hours then it was concentrated undervacuum. The resulting residue was taken up in methanol and then combinedwith sodium methoxide (3.7 mL of 25% in methanol, 16 mmol). The reactionmixture was stirred at ambient temperature overnight. The methanol wasevaporated off and the resulting residue was purified by columnchromatography (silica gel eluting with 95:5 dichloromethane:methanol)to provide a brown solid. This solid was recrystallized fromacetonitrile to provide 550 mg of2-butyl-7-methyloxazolo[4,5-c]quinolin-4-amine as fine tan needles, m.p.187-188° C. Analysis: Calculated for C₁₅H₁₇N₃O+0.1 H₂O: %C, 70.07; %H,6.74; %N, 16.34; Found: %C, 70.07; %H, 6.49; %N, 16.58.

Example 47

Part A

Under a nitrogen atmosphere a mixture of 3-amino-7-methyl-4-quinolinol(3.4 g, 20 mmol) and butyric anhydride (16 mL) were heated at refluxovernight. The reaction mixture was allowed to cool to ambienttemperature and then it was poured over ice. The mixture was adjusted topH 12 with 10% sodium hydroxide and then extracted with dichloromethane.The extract was dried over magnesium sulfate and then concentrated undervacuum. The residue still contained anhydride so it was combined with10% sodium hydroxide and stirred for 1 hour at ambient temperature. Themixture was extracted with dichloromethane. The extract was dried overmagnesium sulfate and then concentrated under vacuum to provide a brownoil. The oil was purified by column chromatography (silica gel elutingwith 3:2 ethyl acetate:dichloromethane) to provide 3.1 g of7-methyl-2-propyloxazolo[4,5-c]quinoline as a light brown oil whichsolidified on standing, m.p. 65-68° C. Analysis: Calculated forC₁₄H₁₄N₂O: %C, 74.31; %H, 6.24; %N, 12.38; Found: %C, 73.69; %H, 6.07;%N, 12.15.

Part B

3-Chloroperoxybenzoic acid (3.8 g of 57-86%) was added to a solution of7-methyl-2-propyloxazolo[4,5-c]quinoline (3 g) in chloroform (100 mL).The reaction mixture was allowed to stir at ambient temperatureovernight. The reaction mixture was washed twice with sodiumbicarbonate, dried over magnesium sulfate and then concentrated undervacuum to provide 3.1 g of7-methyl-2-propyloxazolo[4,5-c]quinolin-5N-oxide as a pale orange solid.

Part C

Under a nitrogen atmosphere, trichloroacetyl isocyanate (2.3 mL, 19.2mmol) was added to a solution of7-methyl-2-propyloxazolo[4,5-c]quinolin-5N-oxide (3.1 g, 12.8 mmol) indichloromethane (100 mL). The reaction mixture was allowed to stir atambient temperature for 3 hours and then the solvent was removed undervacuum. Methanol (100 mL) was added to the resulting orange residuefollowed by sodium methoxide (2.9 mL of 25% in methanol, 12.8 mmol). Thereaction mixture was stirred at ambient temperature overnight. Theresulting precipitate was isolated by filtration and then recrystallizedfrom isopropanol to provide 450 mg of7-methyl-2-propyloxazolo[4,5-c]quinolin-4-amine as a white solid, m.p.188-189° C. Analysis: Calculated for C₁₄H₁₅N₃O+0.2 H₂O: %C, %H, 6.34;%N, 17.16; Found: %C, 68.44; %H, 6.11; %N, 17.42.

Example 48

Part A

Under a nitrogen atmosphere, 3-fluoroaniline (50.0 g, 0.45 mol) anddiethyl ethoxymethylmalonate (91 mL, 0.45 mol) were combined and heatedat 100° C. for 3 hours. The reaction was allowed to cool to ambienttemperature and it solidified. Dowtherm A (200 mL) was added and thereaction mixture was heated at 240° C. for 4 hours. The reaction mixturewas allowed to cool to ambient temperature. The resulting precipitatewas isolated by filtration, washed with hexane and then dried in avacuum oven to provide 71.5 g of ethyl7-fluoro-4-hydroxy-3-quinolinecarboxylate.

Part B

A suspension of ethyl 7-fluoro-4-hydroxy-3-quinolinecarboxylate (65 g,0.28 mol) in 10% sodium hydroxide (250 mL) was heated at reflux for 3hours during which time a solution was obtained. The reaction mixturewas allowed to cool to ambient temperature and then it was filteredthrough filter paper under vacuum. The filtrate was acidified withconcentrated hydrochloric acid. The resulting precipitate was collected,washed with water and then dried to provide 53.5 g of7-fluoro-4-hydroxy-3-quinolinecarboxylic acid as a white solid.

Part C

7-Fluoro-4-hydroxy-3-quinolinecarboxylic acid (25 g) was placed in around bottom flask and heated to 330-350° C. at which time carbondioxide liberation commenced and the material began to liquefy. Afterabout 2 minutes an additional 25 g of7-fluoro-4-hydroxy-3-quinolinecarboxylic acid was added. The heating wascontinued for an additional 4 to 6 minutes at which time there was nofurther evolution of carbon dioxide. The solution was allowed to cool toambient temperature. The resulting solid was isolated by filtration toprovide 35.6 g of 7-fluoro-4-quinolinol as a pink solid.

Part D

Nitric acid (20 mL of 70%) was added to a hot (125° C.) solution of7-fluoro-4-quinolinol (35 g, 214 mmol) in propionic acid (200 mL). Thereaction mixture was stirred at 125° C. for about 1.5 hours and thenallowed to cool to ambient temperature. The resulting yellow precipitatewas isolated by filtration, rinsed with water and then with ethanol, andthen recrystallized from N,N-dimethylformamide/water to provide 18 g of7-fluoro-3-nitro-4-quinolinol.

Part E

A mixture containing 7-fluoro-3-nitro-4-quinolinol (17 g, 81.7 mmol),ammonium hydroxide (80 mL), methanol (200 mL) and palladium on carbon (1g of 10% was placed on a Parr apparatus under a hydrogen atmosphere ofabout 30 psi (2.1 Kg/cm²) for 1 hour. The reaction mixture was filteredto remove the catalyst. The filtrate was treated with charcoal thenconcentrated under vacuum to provide a dark tan solid which turned avery dark brown upon oven drying. The solid was dissolved in methanolthen hydrochloric acid in diethyl ether was added. A gray precipitateformed almost immediately. The suspension was stirred at ambienttemperature for several hours. The precipitate was isolated byfiltration and rinsed well with ether to provide 6.6 g of3-amino-7-fluoro-4-quinolinol hydrochloride.

Part F

Under a nitrogen atmosphere, 3-amino-7-fluoro-4-quinolinol hydrochloride(3.4 g, 19.1 mmol), triethylamine (2.9 mL, 21.0 mmol) and butyricanhydride (15.6 mL, 95.5 mmol) were combined and heated at reflux forabout 18 hours. The reaction mixture was poured over ice and made basicto about pH 12 with 10% sodium hydroxide. The resulting suspension wasstirred until all of the ice had melted then it was extracted withdichloromethane. The extract was dried over magnesium sulfate and thenconcentrated under vacuum to provide an oil. The oil was purified bycolumn chromatography (silica gel eluting initially with dichloromethaneand then with 9:1 dichloromethane:methanol) to provide 2.6 g of7-fluoro-2-propyloxazolo[4,5-c]quinoline as a light brown solid.

Part G

7-Fluoro-2-propyloxazolo[4,5-c]quinoline (2.6 g, 11.3 mmol),3-chloroperoxybenzoic acid (3.3 g of 57-86%) and chloroform (90 mL) werecombined and stirred at ambient temperature for about 3 hours. Analysisby thin layer chromatography (silica gel eluting with 95:5dichloromethane:methanol) showed starting material. An additional 0.5equivalent of 3-chloroperoxybenzoic acid was added and the reaction wasstirred at ambient temperature for another 2 hours at which time thinlayer chromatography showed no starting material. The reaction mixturewas diluted with dichloromethane and then washed twice with sodiumbicarbonate. The organic layer was dried over magnesium sulfate and thenconcentrated under vacuum to provide 2.8 g of7-fluoro-2-propyloxazolo[4,5-c]quinolin-5N-oxide as a yellow-orange oilysolid.

Part H

Under a nitrogen atmosphere, trichloroacetyl isocyanate (2.0 mL, 17.0mmol) was added to a solution of7-fluoro-2-propyloxazolo[4,5-c]quinolin-5N-oxide (2.8 g, 11.3 mmol) indichloromethane (50 mL). The reaction mixture was stirred at ambienttemperature for 3 hours and then the dichloromethane was removed undervacuum. The residue was dissolved in methanol and then combined withsodium methoxide (2.4 mL of 25% in methanol, 11.3 mmol). The reactionmixture was stirred at ambient temperature overnight then filtered toremove a small amount of solid material. The filtrate was concentratedunder vacuum. The residue was dissolved in dichloromethane, dried overmagnesium sulfate and then concentrated under vacuum to provide a brownoil. The oil was purified by column chromatography (silica gel elutingwith 95:5 dichloromethane:methanol) to provide a light brown stickysolid. This material was recrystallized from acetonitrile to provide 200mg of 7-fluoro-2-propyloxazolo[4,5-c]quinolin-4-amine as a rust coloredpowder, m.p. 184-187° C. Analysis: Calculated for C₁₃H₁₂FN₃O: %C, 63.67;%H, 4.93; %N, 17.13; Found: %C, 63.43; %H, 4.57; %N, 16.74.

Example 49

Part A

Under a nitrogen atmosphere, triethylamine (6.4 mL, 46.2 mmol) was addedto a suspension of 3-amino-7-fluoro-4-quinolinol hydrochloride (3 g,14.0 mmol) in tetrahydrofuran (50 mL). Butyryl chloride (1.6 mL, 15.4mmol) was added dropwise at ambient temperature. The reaction mixturewas stirred at ambient temperature for 4 hours. Aqueous sodiumbicarbonate was added and the reaction mixture was allowed to stir atambient temperature for about 1 hour. The resulting biphasic mixture wasfiltered to remove solids. The solids were rinsed with diethyl ether toprovide a slightly pink powder. The tetrahydrofuran layer wasconcentrated under vacuum to provide a dark pink solid. This solid wastriturated with ether and then oven dried. The solids were combined toprovide 3.0 g of N-(7-fluoro-4-hydroxyquinolin-3-yl)butanamide. A 300 mgportion was recrystallized from ethyl acetate/ethanol to provide a lightgray fluffy solid, m.p. 306-308° C. Analysis: Calculated forC₁₃H₁₃FN₂O₂: %C, 62.90; %H, 5.28; %N, 11.28; Found: %C, 62.95; %H, 5.34;%N, 11.14.

Part B

Under a nitrogen atmosphere, phosphorus pentasulfide (4.7 g, 10.5 mmol)was added to a mixture of N-(7-fluoro-4-hydroxyquinolin-3-yl)butanamide(2.6 g, 10.5 mmol) and pyridine (80 mL). The reaction mixture was heatedat reflux for 2 hours and then allowed to cool to ambient temperature.The reaction mixture was extracted with sodiumbicarbonate/dichloromethane. The organic layer was separated, washedtwice with water, dried over magnesium sulfate and then concentratedunder vacuum to provide a rust colored solid. This material wasrecrystallized from methanol to provide 1.8 g of7-fluoro-2-propylthiazolo[4,5-c]quinoline as rust colored platelikeneedles.

Part C

3-Chloroperoxybenzoic acid (2.1 g of 57-86%) was added to a solution of7-fluoro-2-propylthiazolo[4,5-c]quinoline (1.8 g, 7.3 mmol) inchloroform (50 mL). The reaction mixture was stirred at ambienttemperature. Analysis by thin layer chromatography (silica gel elutingwith 95:5 dichloromethane:methanol) showed starting material so anadditional 0.5 equivalent of 3-chloroperoxybenzoic acid was added. Thereaction mixture was stirred at ambient temperature overnight. Thereaction mixture was washed twice with sodium bicarbonate, dried overmagnesium sulfate and then concentrated under vacuum to provide 1.8 g of7-fluoro-2-propylthiazolo[4,5-c]quinolin-5N-oxide as a pale orangesolid.

Part D

Under a nitrogen atmosphere, trichloroacetyl isocyanate (1.2 mL, 10.4mmol) was added to a mixture of7-fluoro-2-propylthiazolo[4,5-c]quinolin-5N-oxide (1.8 g, 6.9 mmol) anddichloromethane (50 mL). The reaction mixture was stirred at ambienttemperature for 2 hours and then concentrated under vacuum to provideN-(7-fluoro-2-propylthiazolo[4,5-c]quinolin-4-yl)trichloroacetamide asan orange oil. The oil was dissolved in methanol and then combined withsodium methoxide (1.5 mL of 25 wt % in methanol). The reaction mixturewas allowed to stir at ambient temperature for 3 hours. The resultingprecipitate was isolated by filtration and then recrystallized firstfrom acetonitrile and then from methanol to provide 1.1 g of7-fluoro-2-propylthiazolo[4,5-c]quinolin-4-amine as a tan powder, m.p.192.5-193.5° C. Analysis: Calculated for C₁₃H₁₂FN₃S: %C, 59.75; %H,4.63; %N, 16.08; Found: %C, 59.55; %H, 4.69; %N, 16.12.

Example 50

Part A

Under a nitrogen atmosphere, a mixture of 3-(trifluoromethyl)aniline (40mL, 0.32 mmol) and diethyl ethoxymethylmalonate was heated at 100° C.for 3 hours. The reaction mixture was allowed to cool to roomtemperature at which time the solution solidified to provide 102 g ofdiethyl 2-{[3-(trifluoromethyl)anilino]methylene}malonate as a creamcolored solid.

Part B

Under a nitrogen atmosphere, a mixture of2-{[3-(trifluoromethyl)anilino]methylene}malonate (80 g, 0.24 mol) andDowtherm A was heated to 240° C. and then stirred for 3 hours. Thereaction mixture was allowed to cool to ambient temperature and thenstirred for 16 hours. The solids were isolated by filtration then washedwith hexane to provide 47.5 g of ethyl4-hydroxy-7-(trifluoromethyl)-3-quinolinecarboxylate as an off-whitesolid.

Part C

A mixture of ethyl 4-hydroxy-7-(trifluoromethyl)-3-quinolinecarboxylate(43.4 g, 0.521 mol) and 10% sodium hydroxide (150 mL) was heated toreflux. Most of the ester did not dissolve so methanol (150 mL) wasadded over the course of an hour to facilitate dissolution. Afterrefluxing for 2 hours a solution was obtained. The solution was refluxedfor an additional 2 hours and then allowed to cool to ambienttemperature overnight. The methanol was removed under reduced pressureand the resulting aqueous solution was acidified with concentratedhydrochloric acid. The resulting precipitate was isolated by filtration,washed with water and then dried in a vacuum oven at 120° C. for 24hours to provide 38.5 g of4-hydroxy-7-(trifluoromethyl)-3-quinolinecarboxylic acid as a whitesolid.

Part D

A round bottom flask was charged with4-hydroxy-7-(trifluoromethyl)-3-quinolinecarboxylic acid (34.1 g, 0.132mol) and then heated in a Wood's metal bath for 5 minutes during whichtime carbon dioxide evolution was observed and the material changed froma solid to a liquid. After 5 minutes no further gas evolution was notedso the flask was removed from the bath and allowed to cool to ambienttemperature. The resulting solid was isolated by filtration to provide27.75 g of 7-(trifluoromethyl)-4-quinolinol.

Part E

A mixture of 7-(trifluoromethyl)-4-quinolinol (22.7 g, 0.106 mol) andpropionic acid (106 mL) was heated to 120° C. Nitric acid (10 mL of 70%)was added dropwise and heating was continued for an additional 2 hours.The reaction mixture was allowed to cool to ambient temperature. Theresulting precipitate was isolated by filtration then washed with waterand diethyl ether to provide 13.3 g of3-nitro-7-(trifluoromethyl)-4-quinolinol as an off-white solid.

Part F

A Parr flask was charged with methanol (40 mL), ammonium hydroxide (10mL), 3-nitro-7-(trifluoromethyl)-4-quinolinol (12.8 g, 49.6 mmol) andpalladium on carbon (1.0 g of 10%). The mixture was placed on a Parrapparatus under a hydrogen atmosphere at 40 psi (2.8 Kg/cm²) for 4hours. The mixture was filtered and the catalyst was washed withmethanol and dichloromethane. The combined organics were concentratedunder vacuum to provide a green solid. The solid was dissolved inmethanol and then combined with 1 N hydrochloric acid in anhydrousdiethyl ether (150 mL). A precipitate formed almost immediately. Thereaction mixture was allowed to stir for 16 hours. The precipitate wasisolated by filtration, washed with diethyl ether and then dried in avacuum oven at 80° C. to provide 9.3 g of3-amino-7-(trifluoromethyl)-4-quinolinol hydrochloride as an off-whitesolid.

Part G

Butyryl chloride (1.5 mL, 14.5 mmol) was added dropwise to a mixture of3-amino-7-(trifluoromethyl)-4-quinolinol hydrochloride (3.5 g, 13.2mmol), triethylamine (6.1 mL, 43.6 mmol) and anhydrous tetrahydrofuran(30 mL). The reaction mixture was allowed to stir for 16 hours. A smallamount of aqueous sodium bicarbonate was added and the reaction mixturewas stirred for 0.5 hours. The tetrahydrofuran was removed under vacuum.The resulting solid was stirred with diethyl ether, isolated byfiltration, washed with water and diethyl ether, and then dried in avacuum oven at 80° C. overnight to provide 3.3 g ofN-[4-hydroxy-7-(trifluoromethyl)quinolin-3-yl]butanamide as a creamcolored solid.

Part H

A mixture of N-[4-hydroxy-7-(trifluoromethyl)quinolin-3-yl]butanamide(3.0 g, 10.05 mmol), phosphorous pentasulfide (4.5 g, 10.05 mmol) andpyridine (30 mL) was heated at reflux for 6 hours. The solution wasallowed to cool to ambient temperature and then it was diluted withdichloromethane and aqueous sodium bicarbonate. The organic layer wasseparated, washed with water and with brine, dried over magnesiumsulfate and then concentrated under vacuum to provide a yellow solid.This material was triturated with hexane and then isolated by filtrationto provide 1.7 g 2-propyl-7-(trifluoromethyl)thiazolo[4,5-c]quinoline asa tan solid. The hexane filtrate was concentrated to give 0.6 g ofadditional product as a yellow solid.

Part I

3-Chloroperoxybenzoic acid (1.93 g, 6.88 mol) was added to a mixture of2-propyl-7-(trifluoromethyl)thiazolo[4,5-c]quinoline (2.0 g, 6.75 mmol)in chloroform (30 mL). The resulting solution was allowed to stir for 24hours. The reaction mixture was diluted with aqueous sodium bicarbonateand then extracted with dichloromethane. The organic layer wasseparated, dried over magnesium sulfate and then concentrated undervacuum to provide 1.98 g of2-propyl-7-(trifluoromethyl)thiazolo[4,5-c]quinolin-5N-oxide as a yellowsolid.

Part J

Under a nitrogen atmosphere, trichloroacetyl isocyanate (0.75 mL, 6.24mmol) was added to a mixture of2-propyl-7-(trifluoromethyl)thiazolo[4,5-c]quinolin-5N-oxide (1.3 g,4.16 mmol) and anhydrous dichloromethane (20 mL). The resulting solutionwas allowed to stir at ambient temperature for 16 hours. The solvent wasremoved under reduced pressure. The resulting residue was dissolved inmethanol (40 mL) then combined with sodium methoxide (1.43 mL of 25% inmethanol, 6.24 mmol). The resulting solution was allowed to stir atambient temperature for 16 hours by which time a precipitate had formed.The precipitate was isolated by filtration, washed with a small amountof methanol and then dried for 16 hours in a vacuum oven at 80° C. toprovide 0.96 g of2-propyl-7-(trifluoromethyl)thiazolo[4,5-c]quinolin-4-amine as a whitesolid, m.p. 215-16° C. Analysis: Calculated for C₁₄H₁₂F₃N₃S: %C, 54.01;%H, 3.89; %N, 13.50; Found: %C, 53.82; %H, 3.66; %N, 13.37.

Example 51

Part A

N⁴-(2-methylpropyl)quinoline-3,4-diamine (5.4 g, 25 mmol) was combinedwith carbon disulfide (9 mL, 150 mmol) and ethanol (55 mL) and thenheated at reflux on a steam bath for 2 hours. The resulting precipitatewas isolated by filtration, washed with ethanol and then air dried toprovide 4.4 g of crude product. A portion (1 g) was dissolved in hotdilute sodium hydroxide and then reprecipitated with acetic acid. Theprecipitate was isolated by filtration while still hot, washed withhexane and then air dried to provide thiazolo[4,5-c]quinoline-2-thiol asa solid, m.p. 282-284° C. Analysis: Calculated for C₁₀H₆N₂S₂: %C, 55.02;%H, 2.77; %N, 12.83: Found: %C, 54.96; %H, 2.69; %N, 12.74.

Part B

Sodium methoxide (15.8 mL of 25% in methanol, 69 mmol) and methyl iodide(3.9 mL, 63 mmol) were added to a solution ofthiazolo[4,5-c]quinoline-2-thiol (13.65 g, 63 mmol) in methanol (160mL). The reaction mixture was heated on a steam bath for 1 hour. Thesolvent was removed under vacuum. The resulting light green-yellow solidwas slurried with water, isolated by filtration, and washed with waterto provide 9.8 g of crude product. A portion (1 g) was recrystallizedfrom methanol to provide 2-(methylthio)thiazolo[4,5-c]quinoline as asolid, m.p. 116-119° C. Analysis: Calculated for C₁₁H₈N₂S₂: %C, 56.87;%H, 3.47; %N, 12.06; Found: %C, 57.09; %H, 3.57; %N, 12.04.

Part C

Peracetic acid (27.8 mL of 32%, 132 mmol) was added to a mixture of2-(methylthio)thiazolo[4,5-c]quinoline (7.7 g, 33 mmol) and acetic acid(100 mL). The reaction mixture was heated at about 60° C. for about 4hours and then at ambient temperature overnight. The resulting yellowprecipitate was isolated by filtration to give 5.6 g of crude product.The filtrate was concentrated under vacuum then the residue was dilutedwith toluene (100 mL). The toluene was removed under vacuum to providean additional 4 g of crude product. A portion (1 g) was recrystallizedfrom N,N-dimethylformamide to provide2-(methylsulfonyl)thiazolo[4,5-c]quinolin-5N-oxide as a yellow solid,m.p. 245-247° C. Analysis: Calculated for C₁₁H₈N₂O₃S₂: %C, 47.13; %H,2.88; %N, 9.99; Found: %C, 47.08; %H, 3.08; %N, 10.14.

Example 52

2-(Methylsulfonyl)thiazolo[4,5-c]quinolin-5N-oxide (2.5 g, 8.9 mmol) andmorpholine (˜50 mL) were combined and then heated on a steam bath for 9hours. The resulting precipitate was isolated by filtration to provide0.9 g of crude product as a yellow solid. The filtrate was cooled in anice bath. The resulting precipitate was isolated by filtration to give0.8 g of crude product as a yellow solid. The two crops were combinedand then a portion (0.5 g) was recrystallized from methanol to provide2-(4-morpholino)thiazolo[4,5-c]quinoline-5N-oxide as a solid, m.p.241-242° C. Calculated for C₁₄H₁₃N₃O₂S: %C, 58.52; %H, 4.56; %N, 14.62;Found: %C, 58.24; %H, 4.38; %N, 14.43.

Example 53

Ammonium hydroxide (18 mL) was added to a mixture of2-(4-morpholino)thiazolo[4,5-c]quinoline-5N-oxide (1.2 g, 4.2 mmol) anddichloromethane (24 mL). The mixture was cooled and then tosyl chloride(0.88 g, 4.6 mmol) in dichloromethane (10 mL) was slowly added. Thereaction mixture was warmed to ambient temperature and then stirredovernight. The organic phase was separated, washed with aqueous sodiumbicarbonate, dried over magnesium sulfate and then concentrated undervacuum to provide crude product as a yellow solid. This material waspurified by column chromatography then dissolved in hydrochloric acidand reprecipitated with sodium hydroxide. The precipitate was isolatedby filtration and then recrystallized twice from methanol to provide0.26 g of 2-(4-morpholino)thiazolo[4,5-c]quinolin-4-amine as a solid,m.p. 225-227° C. Analysis: Calculated for C₁₄H₁₄N₄OS: %C, 58.72; %H,4.93; %N, 19.57; Found: %C, 58.47; %H, 4.63; %N, 19.23.

Example 54

Part A

2-(Methylsulfonyl)thiazolo[4,5-c]quinolin-5N-oxide (2.5 g, 8.9 mmol) andpyrrolidine (˜70 mL) were combined and then refluxed on a steam bath for3 days. The resulting yellow precipitate was isolated by filtration toprovide 0.4 g of 2-(1-pyrrolidino)thiazolo[4,5-c]quinoline-5N-oxide. Thefiltrate was cooled in an ice bath. The resulting precipitate wasisolated by filtration to provide 0.7 g of2-(1-pyrrolidino)thiazolo[4,5-c]quinoline-5N-oxide as a yellow solid.The two crops were combined.

Part B

Ammonium hydroxide (12 mL) was added to a mixture of2-(1-pyrrolidino)thiazolo[4,5-c]quinoline-5N-oxide (0.8 g, 2.95 mmol)and dichloromethane (50 mL). The mixture was cooled and then tosylchloride (0.6 g, 3.2 mmol) in dichloromethane (10 mL) was slowly added.The reaction mixture was warmed to ambient temperature and then stirredovernight. The organic phase was separated, washed with saturatedaqueous sodium bicarbonate and then concentrated under vacuum to providecrude product as a yellow solid. This material was purified by flashcolumn chromatography then slurried with hot methanol, cooled andisolated by filtration to provide 0.14 g of2-(1-pyrrolidino)thiazolo[4,5-c]quinolin-4-amine as a solid, m.p.259-261° C. Analysis: Calculated for C₁₄H₁₄N₄S: %C, 62.20; %H, 5.22; %N,20.49; Found: %C, 61.76; %H, 5.25; %N, 20.72.

Example 55

2-Propylthiazolo[4,5-c]quinolin-4-amine (3.0 g, 12.3 mmol) and1-hydroxy-2-napthoic acid (2.3 g, 12.3 mmol) were separately dissolvedin methanol with the use of dichloromethane if necessary. The twosolutions were combined and the resulting solution was reduced involume. The resulting precipitate was isolated by filtration to provide3.6 g of 2-propylthiazolo[4,5-c]quinolin-4-amine xinofoate as acolorless crystalline solid, m.p. 185-189° C. (decomposed). Analysis:Calculated for C₂₄H₂₁N₃O₃S: %C, 66.80; %H, 4.91; %N, 9.74; Found: %C,66.71; %H, 5.07; %N, 9.78.

Example 56

A solution of 3-hydroxy-2-naphthoic acid (1.9 g, 10 mmol) in methanol(30 mL) was added to a solution of2-propylthiazolo[4,5-c]quinolin-4-amine (2.4 g, 10 mmol) in hot methanol(70 mL). A precipitate formed immediately. The mixture was heated anadditional 5 minutes and then allowed to cool to ambient temperature.The precipitate was isolated by filtration, washed with methanol anddried to provide 4.0 g of product as a tan powder. This material wasrecrystallized from methanol/dichloromethane to provide 3.2 g of2-propylthiazolo[4,5-c]quinolin-4-amine 3-hydroxy-2-naphthoate as awhite powder. Calculated for C₂₄H₂₁N₃O₃S: %C, 66.80; %H, 4.91; %N, 9.74;Found: %C, 66.28; %H, 4.92; %N, 9.59.

Example 57

Part A

A mixture containing 3-nitro[1,5]naphthyridin-4-ol (7.5 g), methanol(200 mL), ammonium hydroxide (50 mL) and 5% platinum on carbon (0.75 g)was placed on a Parr apparatus for 6 hours. The reaction mixture wasfiltered to remove catalyst and then filtered a second time usingCelite® filter aid. The filtrate was concentrated under vacuum toprovide 6.1 g of 3-amino[1,5]naphthyridin-4-ol as a brown solid.

Part B

Valeryl chloride (4.3 g, 35 mmol) was added dropwise to a suspension of3-amino[1,5]naphthyridin-4-ol (5.2 g, 32 mmol) in pyridine (100 mL). Thereaction mixture was heated at reflux for 2 hours. The pyridine wasremoved. The resulting residue was taken up in hot water and thenallowed to cool. The resulting gray precipitate was isolated byfiltration, washed well with hot water and then oven dried to provide2.3 g of N-(4-hydroxy[1,5]naphthyridin-3-yl)pentamide as a gray solid.

Part C

Phosphorous pentasulfide (4.2 g, 9.4 mmol) was added to a suspension ofN-(4-hydroxy[1,5]naphthyridin-3-yl)pentamide (2.3 g, 9.4 mmol) inpyridine (150 mL). The reaction mixture was heated at reflux for 2hours. The pyridine was removed. The resulting residue was taken up in amixture of water, 10% sodium carbonate and 10% sodium hydroxide (anamount sufficient to adjust the pH to >8) and then extracted twice withdichloromethane. The dichloromethane extracts were combined, washed withbrine, dried and then concentrated under vacuum. The residue was dilutedwith toluene and then concentrated under vacuum to provide 2 g of ablack syrup. This material was purified using silica gel columnchromatography to provide 1.4 g of2-butylthiazolo[4,5-c][1,5]naphthyridine as an amber liquid. Highresolution mass spec (EI): Calculated for C₁₃H₁₃N₃S (M+) 243.0830; Found243.0825.

Part D

A solution of 3-chloroperoxybenzoic acid (1.1 g of 57-86%) in chloroform(50 mL) was added in a steady stream to a solution of2-butylthiazolo[4,5-c][1,5]naphthyridine (1.4 g, 5.8 mmol) in chloroform(100 mL). The reaction mixture was stirred at ambient temperature for2.5 hours and then it was diluted with dichloromethane, washed twicewith 10% sodium hydroxide, washed with brine, dried and concentratedunder vacuum to provide a light yellow syrup which solidified onstanding. This material was purified by silica gel column chromatographyto provide 1.2 g of a pale yellow solid. This material wasrecrystallized from petroleum ether (15 mL) and hexanes (100 mL) toprovide 2-butylthiazolo[4,5-c][1,5]naphthyridine-5N-oxide, m.p. 65-69°C. Analysis: Calculated for C₁₃H₁₃N₃OS: %C, 60.21; %H, 5.05; %N, 16.20;Found: %C, 60.43; %H, 5.17; %N, 16.18. High resolution mass spec (EI):Calculated for C₁₃H₁₃N₃OS(M+) 259.0779; Found 259.0789.

Example 58

A solution of 2-butylthiazolo[4,5-c][1,5]naphthyridine-5N-oxide (0.5 g,1.9 mmol) in dichloromethane (100 mL) was cooled in an ice bath. Asolution of trichloroacetyl isocyanate (0.4 g, 2.1 mmol) indichloromethane (25 mL) was added dropwise. The reaction mixture wasstirred at ambient temperature for 8 hours. Added an amount of ammoniain methanol sufficient to make the reaction mixture basic and then letstand overnight. The reaction mixture was diluted with additionaldichloromethane and then washed twice with 10% sodium hydroxide, washedwith brine, dried and concentrated under vacuum to provide 0.6 g of apale yellow solid. This material was purified by silica gel columnchromatography and then recrystallized from acetonitrile (8 mL) toprovide 0.15 g of 2-butylthiazolo[4,5-c][1,5]naphthyridin-4-amine as awhite crystalline solid, m.p. 136-138° C. Analysis: Calculated forC₁₃H₁₄N₄S: %C, 60.44; %H, 5.46; %N, 21.69; Found: %C, 60.12; %H, 5.42;%N, 21.51. High resolution mass spec (EI) Calculated for C₁₃H₁₄N₄S (M+)258.0941 Found: 258.0939. NMR chemical shifts in CDCl3 (ppm) 8.637 dd(1H, J=3.6; 1.2 Hz), 8.048 dd (1H, J=8.5; 1.2 Hz), 7.486 dd (1H, J=8.5;3.6 Hz), 5.691 bs(2H), 3.196 t (2H, J=7 Hz), 1.918 quintet (2H, J=7Hz),1.509 sextet (2H, J=7 Hz), 1.003 t (3H, J=7 Hz).

Example 59

Part A

Using the general method of Example 57 Part B,3-amino[1,5]naphthyridin-4-ol (1.8 g, 11.2 mmol) was reacted withbutyryl chloride (1.3 g, 12.3 mmol) to provide 1.2 g ofN-(4-hydroxy[1,5]naphthyridin-3-yl)butanamide as a charcoal gray solid,m.p.>360° C.

Part B

Using the general method of Example 57 Part C,N-(4-hydroxy[1,5]naphthyridin-3-yl)butanamide (1.2 g, 5.2 mmol) wasreacted with phosphorous pentasulfide (2.3 g, 5.2 mmol) to provide 0.9 gof 2-propylthiazolo[4,5-c][1,5]naphthyridine as an amber syrup.

Part C

Using the general method of Example 57 Part D,2-propylthiazolo[4,5-c][1,5]naphthyridine (0.9 g, 3.9 mmol) was oxidizedto provide 0.7 g of 2-propylthiazolo[4,5-c][1,5]naphthyridin-5N-oxide asa pale yellow solid, m.p. 139-142° C. Analysis: Calculated forC₁₂H₁₁N₃OS: %C, 58.76; %H, 4.52; %N, 17.13; Found: %C, 58.66; %H, 4.59;%N, 17.16. High resolution mass spec: (EI) calculated for C₁₂H₁₁N₃OS(M+) 245.0623; Found 245.0612.

Example 60

Using the general method of Example 58,2-propylthiazolo[4,5-c][1,5]naphthyridin-5N-oxide (0.5 g, 2 mmol) wasaminated to provide 0.2 g of2-propylthiazolo[4,5-c][1,5]naphthyridin-4-amine as ivory needles, m.p.135-136° C. Analysis: Calculated for C₁₂H₁₂N₄S: %C, 58.99; %H, 4.95; %N,22.93; Found: %C, 59.06; %H, 4.96; %N, 22.97. High resolution mass spec(EI) Calculated for C₁₂H₁₂N₄S (M+) 244.0783; Found 244.0785.

Example 61

Part A

A suspension of 3-nitropyridin-4-ol (1.0 g, 7.1 mmol) in methanol (110mL) and a small amount of raney nickel catalyst were combined in a Parrbottle and hydrogenated for 4 hours. The reaction mixture was acidifiedwith a solution of hydrochloric acid in ethanol and then filtered toremove catalyst. The filtrate was refiltered using Celite filter aid.The filtrate was concentrated under vacuum to provide 1.2 g of3-aminopyridin-4-ol as a brown powder, m.p. 199-200° C.

Part B

N,N-diisopropylethylamine (33 mL, 180 mmol) was added to a suspension of3-aminopyridin-4-ol (8.5 g, 46 mmol) in dichloromethane (100 mL). Asolution of butyryl chloride (5.4 g, 51 mmol) in dichloromethane (100mL) was added dropwise. The reaction mixture was stirred at ambienttemperature for 3 hours and then at reflux for 3 hours. The reactionmixture was filtered to remove a black precipitate. The filtrate wasconcentrated under vacuum. The resulting light brown residue wastriturated with hot ethyl acetate (250 mL) and then allowed to coolovernight. The mixture was filtered to remove solids (9.1 g) and thesolids were washed with fresh ethyl acetate. The filtrate wasconcentrated under vacuum to provide 13 g of a light amber syrup. Thesyrup was dissolved in water and then extracted twice with ethylacetate. The extracts were combined, washed with brine, dried and thenconcentrated under vacuum to provide 2.5 g of an amber syrup. Thismaterial was purified by column chromatography to provide 1.2 g ofN-(4-hydroxypyrid-3-yl)butanamide as a light amber syrup whichsolidified on standing.

Part C

Using the general method of Example 57 Part C,N-(4-hydroxypyrid-3-yl)butanamide (1.1 g, 6.1 mmol) was reacted withphosphorous pentasulfide (2.7 g, 6.1 mmol) to provide 0.4 g of2-propylpyrido[3,4-d][1,3]thiazole as an amber syrup, which solidifiedon standing, mp 44-47° C.

Part D

Using the general method of Example 57 Part D,2-propylpyrido[3,4-d][1,3]thiazole (0.4 g, 2.2 mmol) was oxidized toprovide 0.2 g of 2-propylpyrido[3,4-d][1,3]thiazol-5N-oxide as shortivory needles after recrystallization from ethyl acetate (7 mL),m.p.137-139° C. Analysis: Calculated for C₉H₁₀N₂OS: %C, 55.65; %H, 5.19;%N, 14.42; Found: %C, 55.47; %H, 5.25; %N, 14.34.

Example 62

A solution of trichloroacetyl isocyanate (0.11 g, 0.6 mmol) indichloromethane (5 mL) was added dropwise to a chilled (ice bath)solution of 2-propylpyrido[3,4-d][1,3]thiazol-5N-oxide (0.1 g, 0.5 mmol)in dichloromethane (20 mL). The reaction mixture was stirred at ambienttemperature for 5 hours. Additional trichloroacetyl isocyanate (0.2 g)was added and the reaction mixture was stirred at ambient temperatureovernight. The reaction mixture was briefly warmed to reflux thenallowed to stir at ambient temperature for about 3 hours. Ammonia wasbubbled into the reaction mixture which was then allowed to stir atambient temperature for 1 hour. The reaction mixture was diluted withdichloromethane, washed twice with 10% sodium hydroxide, washed withbrine, dried and then concentrated under vacuum to provide an ambersyrup. The reaction was repeated on the same scale. The products werecombined to provide 0.1 g of an amber syrup. This material was purifiedby semi-preparative HPLC on a Gilson system (Rainin Microsorb C18column, 21.4×250 mm, 8 micron particle size, 60A pore, 10 mL/min.,gradient elution from 2-95% B in 25 min., hold at 95% B for 5 min.,where A=0.1% trifluoroacetic acid/water and B=0.1% trifluoroaceticacid/acetonitrile, peak detection at 254 nm for triggering fractioncollection). The semi-prep HPLC fractions were analyzed by LC-APCI/MSand the appropriate fractions were lyophilized to provide the desiredproduct as a trifluoroacetate salt m.p. 160-162° C. Analysis: Calculatedfor C₉H₁₁N₃S+CF₃C(O)₂H: %C, 42.99; %H, 3.94; %N, 13.67; Found: %C,42.84; %H, 3.98; %N, 13.52. High resolution mass spec: (EI) calculatedfor C₉H₁₁N₃S (M+) 193.0674; Found 193.0681.

Example 63

Part A

7-Chloro-4-hydroxyquinoline (35 g, 0.195 mol; available from Aldrich,Milwaukee, Wis.) and nitric acid (350 mL of 70%) were combined andheated at reflux for 75 minutes. The reaction mixture was poured overice while still hot. The resulting bright yellow precipitate wasisolated by filtration and then washed 3 times with boiling ethylacetate to provide 17.3 g of 7-chloro-3-nitro-4-hydroxyquinoline as apale yellow solid.

Part B

7-Chloro-3-nitro-4-hydroxyquinoline (4.48 g, 20 mmol), tin (II) chloridedihydrate (22.6 g, 100 mmol) and ethanol (200 mL) were combined and thenheated at reflux for 4 hours. The reaction mixture was cooled to ambienttemperature and then poured into water (250 mL). The mixture was broughtto neutral pH by the addition of saturated sodium bicarbonate and thenfiltered to remove tin salts. The filtrate was extracted with ethylacetate. The combined organic fractions were dried over magnesiumsulfate, filtered and then concentrated under vacuum to provide 1.8 g of3-amino-7-chloro-4-hydroxyquinoline as a green powder.

Part C

Under a nitrogen atmosphere, butyryl chloride (0.76 mL, 7.3 mmol) wasadded dropwise to a mixture of 3-amino-7-chloro-4-hydroxyquinoline (1.3g, 6.7 mmol), triethylamine (3.0 mL, 21.5 mmol) and anhydroustetrahydrofuran (20 mL). The reaction mixture was maintained at ambienttemperature overnight. The resulting precipitate was isolated byfiltration, washed with water followed by tetrahydrofuran, and thenvacuum dried to provide 1.05 g ofN-(7-chloro-4-hydroxyquinolin-3-yl)butanamide as a tan powder.

Part D

A mixture of N-(7-chloro-4-hydroxyquinolin-3-yl)butanamide (0.9 g, 3.4mol), phosphorous pentasulfide (1.51 g, 3.4 mmol) and pyridine (25 mL)was refluxed under a nitrogen atmosphere for 2.5 hours and then allowedto cool to ambient temperature. The reaction mixture was partitionedbetween dichloromethane (100 mL) and saturated sodium bicarbonate (100mL). The aqueous layer was extracted with dichloromethane (2×100 mL).The organic fractions were combined, washed with water, dried overmagnesium sulfate, filtered and then concentrated under vacuum toprovide crude product. This material was purified by silica gelchromatography, (97:3 dichloromethane:methanol, 10 g SiO₂) to provide0.62 g of 7-chloro-2-propylthiazolo[4,5-c]quinoline as a golden yellowsolid.

Part E

Under a nitrogen atmosphere 3-chloroperoxybenzoic acid (0.7 g of 57-86%)was added to a mixture of 7-chloro-2-propylthiazolo[4,5-c]quinoline (0.5g, 1.9 mmol) and chloroform (20 mL). After 2 hours at ambienttemperature additional 3-chloroperoxybenzoic acid (0.2 g) was added andthe reaction mixture was maintained at ambient temperature for 14 hours.The reaction mixture was diluted with dichloromethane and then washedtwice with saturated sodium bicarbonate. The organic fraction was driedover magnesium sulfate, filtered and then concentrated under vacuum toprovide 0.52 g of 7-chloro-2-propylthiazolo[4,5-c]quinoline-5N-oxide asan orange solid.

Part F

Under a nitrogen atmosphere trichloroacetyl isocyanate (0.32 mL, 2.7mmol) was added to a mixture of7-chloro-2-propylthiazolo[4,5-c]quinoline-5N-oxide (0.50 g, 1.8 mmol)and dichloromethane (20 mL). The reaction mixture was maintained atambient temperature for 2 hours and then concentrated under vacuum. Theresulting oily residue was dissolved in methanol (10 mL), sodiummethoxide (1 mL of 25%, 4.4 mmol) was added and the reaction mixture wasmaintained at ambient temperature for 2.5 days. The resultingprecipitate was isolated by filtration and washed with hexane to provide0.28 g of the desired product as a golden yellow powder. A 50 mg portionwas recrystallized from methanol to provide7-chloro-2-propylthiazolo[4,5-c]quinolin-4-amine as a golden yellowcrystalline solid, m.p. 159-160° C. ¹H NMR (300 MHz, DMSO-d6) δ7.82 (d,J=8.5 Hz, 1H), 7.60 (d, J=2.0 Hz, 1H), 7.27 (dd, J=8.5, 2.1 Hz, 1H),7.10 (s, 2H), 3.16 (t, J=7.4 Hz, 2H), 1.87 (sextet, J=7.4 Hz, 2H), 1.02(t, J=7.4 Hz, 3H); MS (EI) m/e 277.0441 (277.0440 calcd forC₁₃H₁₂ClN₃S).

Example 64

Part A

3-Methoxyaniline (12.3 g, 0.1 mol) and diethyl ethoxymethylenemalonate(21.6 g, 0.1 mol) were combined and heated at 120° C. for 3 hours. Thereaction mixture was allowed to cool to ambient temperature and thenplaced under vacuum overnight to provide 28.5 g of diethyl2-[3-(methoxyanilino)methylene]malonate as an orange oil.

Part B

Dowtherm A (˜200 mL) was charged into a flask equipped with a stir bar,nitrogen inlet, Dean-Stark trap and condenser. The solvent was heated toa vigorous reflux and then 2-[3-(methoxyanilino)methylene]malonate (20.0g, 68 mmol) was added. The reaction mixture was heated for 0.5 hr. andthe brown solution was allowed to cool to ambient temperature. Theresulting precipitate was isolated by filtration, washed with acetoneand then air dried to provide 12.5 g of ethyl4-hydroxy-7-methoxyquinoline-3-carboxylate as a yellow powder.

Part C

A suspension of ethyl 4-hydroxy-7-methoxyquinoline-3-carboxylate (12.0g, 48 mmol) in 10% sodium hydroxide/water (200 mL) was heated at refluxfor 1.5 hr. The reaction mixture was allowed to cool to ambienttemperature and then made acidic (pH=3) by the dropwise addition ofconcentrated hydrochloric acid. The resulting precipitate was isolatedby filtration, washed twice with water and then dried overnight in avacuum oven at 80° C. to provide 10.4 g of4-hydroxy-7-methoxyquinoline-3-carboxylic acid.

Part D

A suspension of 4-hydroxy-7-methoxyquinoline-3-carboxylic acid (4.0 g)in Dowtherm A (75 mL) was heated at reflux for 2 hrs. The resultingbrown solution was allowed to slowly cool to ambient temperature. Theresulting precipitate was isolated by filtration and then dried in avacuum oven at 80° C. for 2.5 days to provide 3.1 g of7-methoxyquinolin-4-ol as a light tan solid.

Part E

A mixture of 7-methoxyquinolin-4-ol (5.0 g, 28.5 mmol) and propionicacid (50 mL) was heated to reflux. Nitric acid (3.2 mL of 70%, 50 mmol)was added dropwise over a period of 15 minutes. The reaction mixture wasrefluxed for 2 hrs and then allowed to cool to ambient temperature. Theresulting precipitate was isolated by filtration, washed with coldethanol followed by hexanes and then dried to provide 3.9 g of7-methoxy-3-nitroquinolin-4-ol as a gray solid.

Part F

7-Methoxy-3-nitroquinolin-4-ol (4.5 g, 20.4 mmol), methanol (250 mL),ammonium hydroxide (5 mL) and palladium on carbon (400 mg of 10%) werecombined. The mixture was placed on a Parr apparatus under a hydrogenatmosphere at 40 psi (2.8 Kg/cm²) for 2 hrs. The reaction mixture wasfiltered. The filtrate was concentrated under vacuum to provide a greensolid. This material was dissolved in methanol (20 mL) and then 1Nhydrochloric acid in diethyl ether (75 mL) was added. The resultingprecipitate was isolated by filtration and dried to provide 2.6 g of3-amino-7-methoxyquinolin-4-ol hydrochloride as a pink solid.

Part G

Butyryl chloride (0.63 mL, 6.1 mmol) was added dropwise to a solutioncontaining 3-amino-7-methoxyquinolin-4-ol hydrochloride (1.0 g, 5.26mmol), triethylamine (2.35 mL, 16.8 mmol), dichloromethane (30 mL) andN,N-dimethylformamide (10 mL). The reaction mixture was maintained atambient temperature overnight. The N,N-dimethylformamide was removedunder vacuum and the resulting solid was partitioned betweendichloromethane (100 mL) and water (100 mL). The organic fraction waswashed with water, dried over magnesium sulfate, filtered and thenconcentrated under vacuum to provide 0.86 g ofN-(4-hydroxy-7-methoxyquinolin-3-yl)butanamide as a tan solid.

Part H

Under a nitrogen atmosphere a mixture ofN-(4-hydroxy-7-methoxyquinolin-3-yl)butanamide (0.66 g, 2.54 mmol),pyridine (20 mL), and phosphorous pentasulfide (1.13 g, 2.54 mmol) washeated at reflux and then cooled to ambient temperature. The reactionmixture was filtered. The filtrate was partitioned betweendichloromethane (100 mL) and saturated sodium bicarbonate (100 mL). Theaqueous fraction was extracted with additional dichloromethane (100 mL).The organic fractions were combined, washed with water, dried overmagnesium sulfate, filtered and then concentrated under vacuum toprovide a solid. This material was purified by silica gel chromatography(15 g of SiO₂ eluting with 95:5 dichloromethane:methanol) to provide0.45 g of 7-methoxy-2-propylthiazolo[4,5-c]quinoline as a pale yellowpowder.

Part I

Using the method of Example 63 Part E,7-methoxy-2-propylthiazolo[4,5-c]quinoline (0.40 g, 1.55 mmol) wasoxidized to provide 7-methoxy-2-propylthiazolo[4,5-c]quinoline-5N-oxideas an orange solid.

Part J

Using the method of Example 63 Part F, the N-oxide from Part I wasreacted with trichloroacetyl isocyanate and the resulting amide washydrolyzed to provide 190 mg of the desired product as an off whitesolid. An analytical sample was obtained by recrystallization frommethanol to provide 7-methoxy-2-propylthiazolo[4,5-c]quinolin-4-amine asoff-white needles, m.p. 152-154° C. ¹H NMR (300 MHz, DMSO-d6) δ7.67 (d,J=8.7 Hz, 1H), 7.06 (d, J=2.4 Hz, 1H), 6.91 (dd, J=8.7, 2.5 Hz, 1H),6.82 (s, 2H), 3.86 (s, 3H), 3.11 (t, J=7.4 Hz, 2H), 1.85 (sextet, J=7.4Hz, 2H), 1.01 (t, J=7.4 Hz, 3H); MS (EI) m/e 273.0934 (273.0936 calcdfor C₁₄H₁₅N₃OS).

Interferon (α) Induction in Human Cells

An in vitro human blood cell system was used to assess interferoninduction by compounds of the invention. Activity is based on themeasurement of interferon secreted into culture media. Interferon ismeasured by bioassay.

Blood Cell Preparation for Culture

Whole blood is collected by venipuncture into EDTA vacutainer tubes.Peripheral blood mononuclear cells (PBM's) are separated from wholeblood by using either LeucoPREP™ Brand Cell Separation Tubes (availablefrom Becton Dickinson) or Ficoll-Paque® solution (available fromPharmacia LKB Biotechnology Inc, Piscataway, N.J.). The PBM's aresuspended at 1×10⁶/mL in RPMI 1640 media (available from GIBC(O), GrandIsland, N.Y.) containing 25 mM HEPES(N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid) and L-glutamine(1% penicillin-streptomycin solution added) with 10% heat inactivated(56° C. for 30 minutes) fetal calf serum added. 200 μL portions of PBMsuspension are added to 96 well (flat bottom) sterile tissue cultureplates (Becton Dickinson Labware, Lincoln Park, N.J.).

Compound Preparation

The compounds are solubilized in ethanol, dimethyl sulfoxide or tissueculture water then diluted with tissue culture water, 0.01N sodiumhydroxide or 0.01N hydrochloric acid (The choice of solvent will dependon the chemical characteristics of the compound being tested.). Ethanolor DMSO concentration should not exceed a final concentration of 1% foraddition to the culture wells. Compounds are initially tested in aconcentration range of from about 0.1 μg/mL to about 5 μg/mL. Compoundswhich show induction at a concentration of 0.5 μg/mL are then tested ina wider concentration range.

Incubation

The solution of test compound is added in a volume (less than or equalto 50 μL) to the wells containing 200 μL of diluted whole blood or ofPBM's in media. Solvent and/or media is added to control wells (wellswith no test compound) and as needed to adjust the final volume of eachwell to 250 μL. The plates are covered with plastic lids, vortexedgently and then incubated for 48 hours at 37° C. with a 5% carbondioxide atmosphere.

Separation

Following incubation, the plates are covered with parafilm and thencentrifuged at 1000 rpm for 10 to 15 minutes at 4° C. in a Damon IECModel CRU-5000 centrifuge. Media (about 200 μL) is removed from 4 to 8wells and pooled into 2 mL sterile freezing vials. Samples aremaintained at −70° C. until analysis.

Interferon Analysis/Calculation

Interferon is determined by bioassay using A549 human lung carcinomacells challenged with encephalomyocarditis. The details of the bioassaymethod have been described by G. L. Brennan and L. H. Kronenberg in“Automated Bioassay of Interferons in Micro-test Plates”, Biotechniques,June/July, 78, 1983, incorporated herein by reference. Briefly statedthe method is as follows: interferon dilutions and A549 cells areincubated at 37° C. for 12 to 24 hours. The incubated cells are infectedwith an inoculum of encephalomyocarditis virus. The infected cells areincubated for an additional period at 37° C. before quantifying forviral cytopathic effect. The viral cytopathic effect is quantified bystaining followed by spectrophotometric absorbance measurements. Resultsare expressed as alpha reference units/mL based on the value obtainedfor NIH HU IF-L standard. The interferon was identified as essentiallyall interferon alpha by testing in checkerboard neutralization assaysagainst rabbit anti-human interferon (beta) and goat anti-humaninterferon (alpha) using A549 cell monolayers challenged withencephalomyocarditis virus.

Compounds of the invention were tested for their ability to induceinterferon in human cells using the test method described above. Theresults are given in the table below where “+” indicates that thecompound induced interferon α at that particular concentration, a “−”indicates that the compound did not induce interferon α at thatparticular concentration, and a “±” indicates that the results wereequivocal at that particular concentration.

Interferon (α) Induction in Human Cells Dose Concentration (μg/mL)Example 0.01 0.05 0.10 0.50 1.0 5.0 10.0 25.0 50.0 2 − − ± + + + not runnot run not run 4 − − − + + + not run not run not run 5 − − −− + + + + + 8 − − − + + + not run not run not run 12 − + + + + + not runnot run not run 14 − − − + + + not run not run not run 16 − − − − + +not run not run not run 18 − − + + + + not run not run not run 20 − − −− − + + + + 22 − − − − − − + + + 24 − − − − − − + + + 26 − − − −− + + + + 28 − − − + + + not run not run not run 30 − − − − + + not runnot run not run 32 − − ± + + + not run not run not run 34 − − − − − −not run not run not run 36 − − − − + + not run not run not run 37 − − −− − − not run not run not run 38 − − − + + + not run not run not run 39− − + + + + not run not run not run 41 + + + + + + not run not run notrun 42 − − − + + + not run not run not run 43 − + + + + + not run notrun not run 44 not run not run − − − + + + + 45 − + + + + + not run notrun not run 46 − + + + + + not run not run not run 47 − + + + + + notrun not run not run 48 − − − + + + not run not run not run 49 − −− + + + not run not run not run 50 not run not run − + + + + + + 53 − −− − − − − + + 54 − − − − − − − + +

Cytokine Induction in Human Cells

An in vitro human blood cell system was used to assess cytokineinduction by compounds of the invention. Activity is based on themeasurement of interferon (α) and tumor necrosis factor (α) (IFN andTNF, respectively) secreted into culture media as described by Testermanet. al. In “Cytokine Induction by the Immunomodulators Imiquimod andS-27609”, Journal of Leukocyte Biology 58, 365-372 (September, 1995).

Blood Cell Preparation for Culture

Whole blood is collected by venipuncture into EDTA vacutainer tubes fromhealthy human donors. Peripheral blood mononuclear cells (PBMCs) areseparated from whole blood by density gradient centrifugation usingHistopaque®-1077 (Sigma Chemicals, St. Louis, Mo.). The PBMCs aresuspended at 3-4×10⁶ cells/mL in RPMI 1640 medium containing 10% fetalbovine serum, 2 mM L-glutamine and 1% penicillin/streptomycin solution(RPMI complete). The PBMC suspension is added to 48 well flat bottomsterile tissue culture plates (Costar, Cambridge, Mass. or BectonDickinson Labware, Lincoln Park, N.J.) containing an equal volume ofRPMI complete media containing test compound.

Compound Preparation

The compounds are solubilized in dimethyl sulfoxide (DMSO). The DMSOconcentration should not exceed a final concentration of 1% for additionto the culture wells. The compounds are generally tested in aconcentration range of from 0.12 to 30 μM.

Incubation

The solution of test compound is added at 60 μM to the first wellcontaining RPMI complete and serial 3 fold dilutions are made. The PBMCsuspension is then added to the wells in an equal volume, bringing thetest compound concentrations to the desired range (0.12 to 30 μM). Thefinal concentration of PBMC suspension is 1.5-2×10⁶ cells/mL. The platesare covered with sterile plastic lids, mixed gently and then incubatedfor 18 to 24 hours at 37° C. in a 5% carbon dioxide atmosphere.

Separation

Following incubation the plates are centrifuged for 5-10 minutes at 1000rpm (˜200×g) at 4° C. The cell culture supernatant is removed with asterile polypropylene pipet and transferred to sterile polypropylenetubes. Samples are maintained at −30 to −70° C. until analysis. Thesamples are analyzed for interferon (α) by either ELISA or bioassay andfor tumor necrosis factor (α) by ELISA.

Interferon Bioassay Analysis

Interferon is determined by bioassay using A549 human lung carcinomacells challenged with encephalomyocarditis. The details of the bioassaymethod have been described by G. L. Brennan and L. H. Kronenberg in“Automated Bioassay of Interferons in Micro-test Plates”, Biotechniques,June/July, 78, (1983), incorporated herein by reference. Briefly statedthe method is as follows: A549 cells are incubated with dilutions ofsamples or a standard interferon at 37° C. for 24 hours. The incubatedcells are then infected with an inoculum of encephalomyocarditis virus.The infected cells are incubated for an additional 24 hours at 37° C.before evaluating for viral cytopathic effect. The viral cytopathiceffect is quantified by staining with crystal violet followed by visualscoring of the plates. Results are expressed as alpha reference units/mLbased on the value obtained for NIH Human Leukocyte IFN standard.

Interferon (α) and Tumor Necrosis Factor (α) Analysis by ELISA

Interferon (α) concentration is determined by ELISA using a HumanMulti-Species kit from PBL Biomedical Laboratories, New Brunswick, N.J.according to the manufacturer's instructions.

Tumor necrosis factor (α) (TNF) concentration is determined using ELISAkits available from Genzyme, Cambridge, Mass.; R&D Systems, Minneapolis,Minn.; or Pharmingen, San Diego, Calif. according to the manufacturer'sinstructions.

In the tables below, a “+” indicates that the compound induced theindicated cytokine at that particular concentration, a “−” indicatesthat the compound did not induce the indicated cytokine at thatparticular concentration, and a “±” indicates that the results wereequivocal at that particular concentration.

Cytokine Induction in Human Cells Interferon (α) Induction TumorNecrosis Factor Induction Dose Concentration (μM) Dose Concentration(μM) Example 0.12 0.37 1.11 3.33 10 30 0.12 0.37 1.11 3.33 10 30 12 − −− + + + + + + + + + 18 − − + + + + + + + + + + 20 − − + − − − − −− + + + 24 − − − − − − − − − − − + 42 − − − − + − − − + + + + 53 − − − −− − − − − − − − 58 − − − − ± ± − + + + + + 60 − − − − − − − ± + + + + 62− − − − − − − − − − − − 63 − − + + + − + + + + + + 64− + + + + + + + + + + +

The present invention has been described with reference to severalembodiments thereof. The foregoing detailed description and exampleshave been provided for clarity of understanding only, and no unnecessarylimitations are to be understood therefrom. It will be apparent to thoseskilled in the art that many changes can be made to the describedembodiments without departing from the spirit and scope of theinvention. Thus, the scope of the invention should not be limited to theexact details of the compositions and structures described herein, butrather by the language of the claims that follow.

We claim:
 1. A compound of formula I:

wherein: R₁ is selected from the group consisting of oxygen, sulfur andselenium; R₂ is selected from the group consisting of -hydrogen; -alkyl;-alkyl-OH; -haloalkyl; -alkenyl; -alkyl-X-alkyl; -alkyl-X-alkenyl;-alkenyl-X-alkyl; -alkenyl-X-alkenyl; -alkyl-N(R₅)₂; -alkyl-N₃;-alkyl-O—C(O)—N(R₅)₂; -aryl; -alkyl-X-aryl; and -alkenyl-X-aryl; R₃ andR₄ join to form a heteroaromatic or heterocyclic ring that contains onenitrogen as the only ring hetero atom; X is selected from the groupconsisting of —O—, —S—, —NR₅—, —C(O)—, —C(O)O—, —OC(O)—, and a bond; andeach R₅ is independently H or C₁₋₈alkyl; or a pharmaceuticallyacceptable salt thereof.
 2. A compound according to claim 1 wherein R₁is oxygen or sulfur.
 3. A compound according to claim 1 wherein R₃ andR₄ are taken together to form a substituted or unsubstituted pyridinering.
 4. A compound according to claim 2 wherein R₃ and R₄ are takentogether to form a substituted or unsubstituted pyridine ring.
 5. Acompound according to claim 1 wherein R₂ is C₁₋₄ alkyl.
 6. A compoundaccording to claim 2 wherein R₂ is C₁₋₄ alkyl.
 7. A compound accordingto claim 1 wherein R₁ is sulfur.
 8. A pharmaceutical compositioncomprising a therapeutically effective amount of a compound of claim 1or a pharmaceutically acceptable salt thereof, with a pharmaceuticallyacceptable carrier.
 9. A compound selected from the group consisting of:2-butylthiazolo[4,5-c][1,5]naphthyridin-4-amine;2-propylthiazolo[4,5-c][1,5]naphthyridin-4-amine; or a pharmaceuticallyacceptable salt thereof.